31 gal here too, sitting in box in the garage, plan on doing body mounts at the same time .
CK5
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1978 Blazer/Jimmy projects
- Thread starter mac907
- Start date
I've got 4 inch tough country rear springs with zero rates and sits level with worn out super lift inch springs up front, I'm guessing there 6 in sagged springs.
Not interested in the body lift. Just going back with rubber.
Not interested in the body lift. Just going back with rubber.
I crawled under the truck las night and wiped off a bunch of grime to get these identiying pics. 1st shot is of the flexplate, which I belive is the correct counterbalanced version.
2nd pic, block stamping. From what I have read, the 509 block is preferable for building due to thicker mains?
3rd pic is of the harmonic balancer, showing the crescent cutout.
Is there any way to tell if I have the right heads without pulling them off? They are externally different from my 350 head in that the temp sensor is on the passenger side instead of the driver side.
2nd pic, block stamping. From what I have read, the 509 block is preferable for building due to thicker mains?
3rd pic is of the harmonic balancer, showing the crescent cutout.
Is there any way to tell if I have the right heads without pulling them off? They are externally different from my 350 head in that the temp sensor is on the passenger side instead of the driver side.
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First pic is the vaccum lines, they're all flexible and free of cracks. Top one off of the thermostat housing goes to the front of the carb, middle one to the distributor, and bottom line to the passenger side of the carb/air filter housing.
2nd pic, no lines hooked up to this item. I think it's some kinda cruise control, so it shouldn't matter right?
3rd pic, I think is maybe the egr? It's between the distributer and back of the carb, not sure if I need to plug the open end of the T or add a line and hook it up somewhere. No emissions here, so if removal would be beneficial I'd see that as an option as well.
4th pic shows my vaccum booster lines and filter replaced as well as the pcv line. Slight improvement in braking if any, so I guess the next step is a remanufacuted booster/master cylinder combo.
The vehicle still shakes while idling stationary in drive, hopefully the carb rebuild will fix this or maybe I'll find something out of place while wiping down the undercarriage.
2nd pic, no lines hooked up to this item. I think it's some kinda cruise control, so it shouldn't matter right?
3rd pic, I think is maybe the egr? It's between the distributer and back of the carb, not sure if I need to plug the open end of the T or add a line and hook it up somewhere. No emissions here, so if removal would be beneficial I'd see that as an option as well.
4th pic shows my vaccum booster lines and filter replaced as well as the pcv line. Slight improvement in braking if any, so I guess the next step is a remanufacuted booster/master cylinder combo.
The vehicle still shakes while idling stationary in drive, hopefully the carb rebuild will fix this or maybe I'll find something out of place while wiping down the undercarriage.
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First thing is to plug that T fitting in the back if it's open and sucking air. I don't see an egr valve. The fitting on top of the waterneck is a temp switch prevents vac advance until engine is at operating temp. I'd bypass that.
What emission laws do yo have there?
What is your timing set at?
Yeah that's for cruise.
Your trans kick down is no connected which is not causing your problems.
Make sure the vac line running down to the back of the trans is connected and not broken.
The vac line running to the air cleaner I'd just plug for now, that's for carb heat(winter).
What emission laws do yo have there?
What is your timing set at?
Yeah that's for cruise.
Your trans kick down is no connected which is not causing your problems.
Make sure the vac line running down to the back of the trans is connected and not broken.
The vac line running to the air cleaner I'd just plug for now, that's for carb heat(winter).
I don't fully understand vaccum lines. Can i just run a line from any vaccum fitting of my choice on the carb to the distributor and then plug up all the other fittings if i am doing the water neck switch/air filter housing bypass? Or is each vaccum fitting on the carb specifically designed for a specific task?
I don't own a timing light yet, so I'm not sure where it's set yet.
Alaska doesn't currently enforce any vehicle emissions. (Even though technically we have federal emissions that are supposed to apply to everyone.)
I don't own a timing light yet, so I'm not sure where it's set yet.
Alaska doesn't currently enforce any vehicle emissions. (Even though technically we have federal emissions that are supposed to apply to everyone.)
Your getting into ported vs manifold full (constant) vacuum, the hose on the front drivers side is Probably ported (no vac at idle) easy to check at idle, rpm will change if you remove it.
Manifold constant vac will be all the time and if used will increase timing in the
distributor and cause engine to idle at a faster rpm.
Which way to go will start the great debate. What works best for your engine is what is correct.
I'd leave it the way it is and bypass that switch.
The T fitting the behind the carb will be constant vac.
The hose coming off the pass side of carb going to the switch and air cleaner is probably constant manifold, but not sure I haven't messed with the older style quads in a while. Cap that off too.
check the vac can on the distributor and make sure it working and not blown internally. If its good you can hook it up to constant vacuum or just suck on the hose while engine is at idle and rpm shoud increase.
Eliminate all vac leaks first.
I think that T fitting being open is part the problem.
At work so I can't elaborate more at the moment but I'm sure others will chime in. Hopefully I didnt confuse you more.
Manifold constant vac will be all the time and if used will increase timing in the
distributor and cause engine to idle at a faster rpm.
Which way to go will start the great debate. What works best for your engine is what is correct.
I'd leave it the way it is and bypass that switch.
The T fitting the behind the carb will be constant vac.
The hose coming off the pass side of carb going to the switch and air cleaner is probably constant manifold, but not sure I haven't messed with the older style quads in a while. Cap that off too.
check the vac can on the distributor and make sure it working and not blown internally. If its good you can hook it up to constant vacuum or just suck on the hose while engine is at idle and rpm shoud increase.
Eliminate all vac leaks first.
I think that T fitting being open is part the problem.
At work so I can't elaborate more at the moment but I'm sure others will chime in. Hopefully I didnt confuse you more.
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Also that white diaphram on the carb needs to be working correctly. Called the choke break. Make sure it moves when vac is applied. When you start the engine the arm on the back should pull in and slightly open the choke flap on a cold start. this will also affect idle quality.
2) Diagnose/Fix engine RPM drop and violent shaking when tranny is shifted into drive.
CHECK
After replacing and capping off what I thought were all the vaccum lines I went on a spree of cleaning all the thick built up grime off the truck. I found a second vaccum inlet on the front of the carb that was camoflauged under a layer of gunk and capped it off yesterday along with the exposed T-fitting in front of the distributor which smoothed out the idle slightly.
Then I got back under the truck and after a bunch of cleaning I made my way back to the tranny/t-case. Tucked behind the tranny crossmember was a completely disconnected vaccum line which I believe may have been the vaccum modulator line mentioned earlier by diesel4me. I reconnected it, started the truck, and instantly the shakey idle problem was fixed.
CHECK
After replacing and capping off what I thought were all the vaccum lines I went on a spree of cleaning all the thick built up grime off the truck. I found a second vaccum inlet on the front of the carb that was camoflauged under a layer of gunk and capped it off yesterday along with the exposed T-fitting in front of the distributor which smoothed out the idle slightly.
Then I got back under the truck and after a bunch of cleaning I made my way back to the tranny/t-case. Tucked behind the tranny crossmember was a completely disconnected vaccum line which I believe may have been the vaccum modulator line mentioned earlier by diesel4me. I reconnected it, started the truck, and instantly the shakey idle problem was fixed.
3) Stop coolant pooling on driver side of intake manifold.
CHECK
Turns out it accumulated while the vehicle was parked for a couple years. After cleaning the coolant off it has not returned.
Thanks blazer74, diesel4me, and all others helping so far. Now that these problems have been fixed the list goes on....
CHECK
Turns out it accumulated while the vehicle was parked for a couple years. After cleaning the coolant off it has not returned.
Thanks blazer74, diesel4me, and all others helping so far. Now that these problems have been fixed the list goes on....
Glad it idles better--good job on the tank too...
As for that modulator hose,if you had driven it you would notice right away the tranny would not upshift until it was racing up to about 3000 rpms,,then when it went to shift into third,you would get the feeling it goes into "neutral" when you let off the gas..the modulator regulates the line pressure and shift points in the tranny,using engine vacuum as a reference..
You say you just plugged off the open port on the "T" fitting--that is the port the modulator is supposed to get its vacuum from--perhaps that line was unplugged at both that T and at the modulator--if so,you will know right away the first time you drive it..the modulator can croak from sitting too,sometimes the diaphram in it fails and lets tranny fluid get sucked into the intake,which can cause damage when it gets low enough of fluid (and make clouds of dense white smoke!)...also the metal can sometimes rusts enough to get a hole in it too..
Your "hard" brake pedal could also be caused by the wheel cylinders or calipers being seized from sitting,or rubber brake hoses that collapsed internally --if it has sat a long time all of those things could have occoured,and I'd really look the metal brake lines over too,even ones that look practically new (like the ones on my truck I replaced 2 years ago),can have one tiny spot thats bubbly and ready to pop on the first panic stop..
I saw just that on mine today,and I'm disgusted!..
As for that modulator hose,if you had driven it you would notice right away the tranny would not upshift until it was racing up to about 3000 rpms,,then when it went to shift into third,you would get the feeling it goes into "neutral" when you let off the gas..the modulator regulates the line pressure and shift points in the tranny,using engine vacuum as a reference..
You say you just plugged off the open port on the "T" fitting--that is the port the modulator is supposed to get its vacuum from--perhaps that line was unplugged at both that T and at the modulator--if so,you will know right away the first time you drive it..the modulator can croak from sitting too,sometimes the diaphram in it fails and lets tranny fluid get sucked into the intake,which can cause damage when it gets low enough of fluid (and make clouds of dense white smoke!)...also the metal can sometimes rusts enough to get a hole in it too..
Your "hard" brake pedal could also be caused by the wheel cylinders or calipers being seized from sitting,or rubber brake hoses that collapsed internally --if it has sat a long time all of those things could have occoured,and I'd really look the metal brake lines over too,even ones that look practically new (like the ones on my truck I replaced 2 years ago),can have one tiny spot thats bubbly and ready to pop on the first panic stop..
I saw just that on mine today,and I'm disgusted!..
Yes brake/calipers are one of my new top three list of priorities, sorry to hear about your line issue.
As far as the T-fitting goes, I'm pretty sure that the side that was already hooked up is going to the tranny's vaccum modulator. With my understanding from blazer74, the T-fitting is a constant/manifold vaccum, so wouldn't it make sense to cap it off if there aren't any accessories under the hood requiring that kind of vaccum (my guess is it used to be for the cruise control when that was hooked up)? Or would the addional vaccum from tieing it into the carb be the way to go?
New Project Priorities:
1) Oil leaking about 1 quart per hour from somewhere on the lower front of the engine.
First I'm replacing the oil pan gasket and if that doesn't work the timing cover gasket.
2) Brakes, a new vaccum booster/master cylinder are going in along with new calipers and soft lines.... maybe hard lines too.
Can I just bolt 3/4 ton HD calipers in place of the 1/2 ton ones? I remember with my other truck I could use either caliper on the same rotor when I did a 14 bolt ff disc conversion.
3) Drivers tail light/turn signal/brake light out.
Looks like a secion of wire is cut out and another is missing.
As far as the T-fitting goes, I'm pretty sure that the side that was already hooked up is going to the tranny's vaccum modulator. With my understanding from blazer74, the T-fitting is a constant/manifold vaccum, so wouldn't it make sense to cap it off if there aren't any accessories under the hood requiring that kind of vaccum (my guess is it used to be for the cruise control when that was hooked up)? Or would the addional vaccum from tieing it into the carb be the way to go?
New Project Priorities:
1) Oil leaking about 1 quart per hour from somewhere on the lower front of the engine.
First I'm replacing the oil pan gasket and if that doesn't work the timing cover gasket.
2) Brakes, a new vaccum booster/master cylinder are going in along with new calipers and soft lines.... maybe hard lines too.
Can I just bolt 3/4 ton HD calipers in place of the 1/2 ton ones? I remember with my other truck I could use either caliper on the same rotor when I did a 14 bolt ff disc conversion.
3) Drivers tail light/turn signal/brake light out.
Looks like a secion of wire is cut out and another is missing.
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There was a few different caliper piston sizes on 10 bolt axles,that will bolt up,they increased the size according to the GVW ratings..you will probably need the matching brake hoses to go with them,the banjo bolts may be different sizes than your originals..
The vacuum ports on any engine should always be capped off if not being used--otherwise idle quality will be affected,dust or dirt could be sucked into the engine too,along with robbing available vacuum for the other devices operated by vacuum..(you may find you brakes work better now that you capped off that open port)..
As for the oil leak,first see if the timing cover has a hole rubbed thru it by the timing chain--it happens on high mileage engines fairly often,the metal will get paper thin,then a slot gets cut all the way thru,and oil leaks all over the front of the engine...a worn harmonic balancer seal will let oil escape too--they sell repair sleeves to cover up the groove in the balancer sleeve the seal cut into it if it has that trouble..if the oil pan is leaking where it meets the timing cover at the rubber "smile"gasket seal,you can often use brake cleaner to wash it off good and then seal it up with some RTV silicone gasket maker like "The Right Stuff" or Permatex black RTV,without having to drop the oil pan..
The wiring is not a big deal to fix,it might pay off to visit a junkyard or look at another truck like yours to determine what might be missing or butchered..
The vacuum ports on any engine should always be capped off if not being used--otherwise idle quality will be affected,dust or dirt could be sucked into the engine too,along with robbing available vacuum for the other devices operated by vacuum..(you may find you brakes work better now that you capped off that open port)..
As for the oil leak,first see if the timing cover has a hole rubbed thru it by the timing chain--it happens on high mileage engines fairly often,the metal will get paper thin,then a slot gets cut all the way thru,and oil leaks all over the front of the engine...a worn harmonic balancer seal will let oil escape too--they sell repair sleeves to cover up the groove in the balancer sleeve the seal cut into it if it has that trouble..if the oil pan is leaking where it meets the timing cover at the rubber "smile"gasket seal,you can often use brake cleaner to wash it off good and then seal it up with some RTV silicone gasket maker like "The Right Stuff" or Permatex black RTV,without having to drop the oil pan..
The wiring is not a big deal to fix,it might pay off to visit a junkyard or look at another truck like yours to determine what might be missing or butchered..
The T fitting fwd side is hooked up to the trans mod, the open end could have gone to the cruise and or a/c controls at one time, there is a metal line screwed into the base of the carb at the rear is the vac for the brakes, it transitions to rubber, make sure that rubber line is not collapsed, also there is check valve on the booster that holds vac in the booster that allows the brakes to work couple of times if the engine quits while driving, run the engine for a minute, shut it off and pull that check valve off the booster. You should still have vac there and here it escape. If not the valve or booster is bad assuming vac is getting to the booster from the engine.
If you need an oil pan gasket look into felpro 1 piece type. Much better and reusable, about 35 bucks.
Id go thru all the brake hydraulics anyway, any bad hard lines will show up even if a visual doesn't show anything.
If you need an oil pan gasket look into felpro 1 piece type. Much better and reusable, about 35 bucks.
Id go thru all the brake hydraulics anyway, any bad hard lines will show up even if a visual doesn't show anything.
I was able to find a guy on craigslist with three 1978 parts trucks; a blazer, a suburban, and a shortbed. I bought the whole rear wiring harness off the blazer for $20. It turns out I only needed the sub-attachment for the left side, so i just plugged the rear turn signal assembly socket into the main rear harness and the wiring problem was fixed.
I also scored a pair of tow hooks along with a nice bumper guard equipped bumper off of the 78' shortbed for an extra $50.
I also scored a pair of tow hooks along with a nice bumper guard equipped bumper off of the 78' shortbed for an extra $50.
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UPDATE.... My 78' Blazer that has been in a performance shop should be ready to take home as early as Tuesday.... I'm super stoked after getting to test drive it, but when I parked it back at the shop the radiator started leaking from a small crack around the filler neck. Paying to get the truck out of the shop is going to leave me quite broke, so I'll probably double stripping down the 78' Jimmy I've been working on (in search of the frontal engine oil leak) as a source of a new radiator for my 78' Blazer.
Question: How difficult would it be to fit the radiator from the Jimmy 400sbc to the Blazer 350sbc setup?
The only difference I can tell is that the radiator for the 400sbc engine is about 2" taller and 1" thicker. Could this be considered a performance cooling upgrade for the 350sbc cooling system or am I overlooking something that makes this not possible or feasible?
Question: How difficult would it be to fit the radiator from the Jimmy 400sbc to the Blazer 350sbc setup?
The only difference I can tell is that the radiator for the 400sbc engine is about 2" taller and 1" thicker. Could this be considered a performance cooling upgrade for the 350sbc cooling system or am I overlooking something that makes this not possible or feasible?
It should be a bolt in swap,and it'll increase the cooling capacity..you will probably need to move the rubber radiator support cushions on the bottom and up under the upper panel you'll have to take off to get the old one out...you might need to drill a few holes to mount them--just copy the way it was installed in the parts truck,you might need or want to use the upper support off that truck to make it an easier swap..
If its just the filler neck leaking and the rest of the radiator is still good,its not that hard to solder the filler neck up with some 50/50 solder and flux...then you wont have to swap that other one in right away,save it for later..
If its just the filler neck leaking and the rest of the radiator is still good,its not that hard to solder the filler neck up with some 50/50 solder and flux...then you wont have to swap that other one in right away,save it for later..
Cool, I haven't brought the Blazer home yet so I don't have it in the same area to compare to the Jimmy. I figured it would be a simple swap that may require swapping the top core support attachment. I do wonder if the 78' Blazer actually originally had a 400sbc, but had the 350sbc swapped in later with a smaller/matching radiator because the current radiator in it rocks back and forth easily while mounted with some room to spare. The Blazer's radiator is a crappy plasitic/aluminum combo so I may Plasti-weld it back together to keep it as a spare, but I'd like to swap in the larger capacity (and also in like new condition) radiator from the Jimmy regardless as an upgrade.
After pulling the rear carpet from the back of the 78' Jimmy and finding a clean bed with perfect original factory green paint on top and original red factory sealer on the under side I've decided the Jimmy is a keeper unless somebody locally makes me a crazy high offer. I'll still use it to feed parts to my Blazer for now, but will replace those parts with upgrades when funds allow. I see an all aluminum BeCool radiator in the future for the Jimmy.
After pulling the rear carpet from the back of the 78' Jimmy and finding a clean bed with perfect original factory green paint on top and original red factory sealer on the under side I've decided the Jimmy is a keeper unless somebody locally makes me a crazy high offer. I'll still use it to feed parts to my Blazer for now, but will replace those parts with upgrades when funds allow. I see an all aluminum BeCool radiator in the future for the Jimmy.
