79' GMC C15 - Spruce Caboose

[bix]

You're giving me wheel envy!

On the fan controller, I'm only running mine because I already have it. I've debated about taking it out but then I figure why bother if it's working fine. Plus as I mentioned it has the soft start feature that I really like.

If the wiring for your Holley system is like mine, the fan triggers are ground wires. You just wire them to the ground side of a relay. Heck, to simplify wiring, you could wire the relay 12V+ trigger wire to the battery feed wire on the relay since it will only come on when the Holley system is powered up.

Haha I think they look awesome too. So stoked to be running the stock centre caps.

Yea both of you guys are right. Why buy and use stuff I don't need to, and like Chevy305 said.. The computer will have exact accuracy on coolant temp rather than a probe in the fins, or having to create a coupler for the thermostat to go into.

 

[Chevy305]

You're giving me wheel envy!

On the fan controller, I'm only running mine because I already have it. I've debated about taking it out but then I figure why bother if it's working fine. Plus as I mentioned it has the soft start feature that I really like.

If the wiring for your Holley system is like mine, the fan triggers are ground wires. You just wire them to the ground side of a relay. Heck, to simplify wiring, you could wire the relay 12V+ trigger wire to the battery feed wire on the relay since it will only come on when the Holley system is powered up.

That's exactly how I have my fan relays wired. 10awg from battery to #30 on the relay with a jumper to the positive coil trigger terminal, and ECM only activates when the key is on so it doesn't matter if fed from constant source if the fans will only trigger with the ECM grounding the relay coil.

 

[bix]

Funny how when it's nice enough to be in the shop now, it's nice enough to be doing everything else to the property..

I got the aux battery tray and it's gonna be a pretty good fit. Core support even has to two punch marks on where to drill for that option.. too easy. That led me to realizing I should do or find some inner fenders, and if I'm gonna do that I gotta prep, and paint the inside of the front fenders and it snowballed quick.
I had one salvageable inner fender, so I gave that a pretty quick n dirty job with a wire wheel and painted it up. Should last a couple years and I'll change it out when funds are better. I did had to buy one inner fender. Only one I could afford to get shipped here right now says it's for a 87 r1500. Hopefully an 87 2wd won't be much different.

I did manage to get the inner fender and two inners painted. It's the one I need for the drivers side battery which will help me out to put a battery in the tray and start modifying the harness to fit.

I bought some pacesetter headers and the drivers side wouldn't fit without some good whiskey dents so I decided to do the adult thing and return them for a refund, and stick with the other crappy headers I have and can't get my money back for.

I was going to spend money on tires but I found a set of 265/65/r17s with not much life but they hold air and will get me through the test and tune process, while also being close enough to the size I want to run that I can check for any clearance issues running a 17x9 up front at full lock ect..

. That leaves me with enough coin to grab the terminator x, that being said it's time to start planning out the wiring. It's such a luxury to be working on a vehicle that's never had a single modification / ****ery done to it.

 

[bix]

Haven't had a nice day lately to clear coat the wheels ,but I did pick up the tires. Brake brackets are still a couple weeks out so I'm focusing on the front of the truck as I can't do much until they arrive..

I got the fenders on, one inner installed, replacement should be here in a couple weeks as well. Aux battery tray mounted, started labeling wires at the bulkhead. And seeing how it all lines up, being on the drivers side. The terminator should be here by the weekend, and next week I'll get around to messing with it. Hoping to fire it up sooner than later, won't be mobile but an open header fire up is almost mandatory, I'd think.. I don't have any money for a dash yet. But I'll use the handheld screen for temp and oil pressure. Also hoping I can use it to monitor oil pressure with the engine off, as I prime the engine first. I was going to use my mechanical gauge but I can't find the metric thread, to 1/4 npt adapter I had laying around...


I'm going to re use the th350 dip stick for the 4l60e. The tab on the original tube was short so cut one off a broken tube I had laying around and got it to work, got some silicone heater hose, so now I can fill the system. I stupidly ordered a stock GMC fan set up because they were on wholesaler clear out ( rock auto ). After thinking about it I figured I should check the length. Turns out the dual fan is going to be way too big so I ordered up a single fan. That's only 16 inches in diameter. I knew guys used Ford Windstar fans... Didn't realize it was a size, and not cost issue.. just another tuition payment is all.



Once the new prop valve arrives I'll be able to hook up to the master and finish that all up and snug down the front end a bit more.

There is so many little things to do.. and I can be a real scatter brain someti...often haha. But it feels good to be getting them done with.

Still need to figure out a the power steering and also connecting to the fuel tank. The fuel rail, to 6 AN fittings I have don't fit, because the piece of fuel line ( hardline at the sender ) is about half inch too long from the raised section,to the end. Causing the adapter to not be threaded on. Can I just cut these to length or will I mess up the sending unit at all? Intuition tells me it'd be fine, but I can't keep buying some things twice haha.

Is it possible to flare stainless steel with a regular flare tool, or will I just mess up my lines like some people say?

 

[bix]

Today I got the replacement door pins and bushing on the passenger side in. Forgot to get two more for the drivers side. I drilled two locating holes in the doors, and in the body to re-align the passenger side since it had zero droop to it. Used a broken drill bit to line it all back up and install. The passenger side door doesn't need any immediate work so it'll get hung so I can line up the fenders and hood. The drivers side door needs a new regulator and I'm still fighting with the vent window removal on that side.


I managed to find the two m16-1.5 to 1/4 NPT thread adapters In the driveway gravel while I was looking for something else my wife dropped. Since I had these I went and pulled the intake, valve covers, installed the mechanical gauge back up from the SBC, used my plant sprayer to pump oil up. Managed to get 40-45 psi and just let it naturally bleed down twice. Nice little puddle of oil at the top of each rocker, makes me a happy camper with that being done. Summit sells an oil priming socket, but I don't believe it's keyed for the stock pump or something. This was free anyway so that works.

 

[mrk5]

Since I'm a design nerd, I like the font on those gauges (Serpentine).

 

[bix]

@mrk5

You and me both! Having been a "graffiti" artist focusing on typography for a big chunk of my life, I always focus on the little things about letters.... I dont think ill need them anymore since ill have a new dash with proper gauges that function. Sucks because i do like the gauges, but having a clean cab will be nicer. I am thinking about mounting this holley PCM somewhere in that area. It might get mounted to where those gauges are now. I would like to be able to see the lights on the holley PCM as its sorta my OBD port so to say... Im not sure if having the handheld mounted in the cab will be the equivalent or not but if it is i could tuck the PCM completely away in the dash or under the seat.

 

[bix]

I think ive decided to mount the PCM up behind the dash tucked away nicely with the heating and venting box. It would give me access to the lights and it basically blends in. It also gives me enough space to have the relay, and the inline fuse for the injectors/coils inside the cab. Ive seen lots of guys go through the 2 inch hole thats in the firewall behind the engine, and slightly on the passenger side. Since my firewall didnt have one of these, i decided to go through the firewall down at the passenger side firewall/kickpanel area. I ordered up some 2 inch grommets and started running a test fit. There is quite a bit of distance in the harness before you have the first pigtail of connectors, so routing the harness down and out this way uses up the slack well and keeps it out of the engine bay. Im also hoping once the inner fender goes in the harness is tucked down there nicely.








I also didnt know the holley kit doesnt come with the coil harness's.. i sold mine with the stock pcm awhile back. I do plan on relocating the coils eventually with some nice sbc looking valve covers, so i ordered a longer coil harness , and hopefully i can just tuck away the extra until then. Its nice that I have the option of operating a DBC throttle body, but its annoying that i cant take the 4 sensors off the harness until i do.. luckily i can tuck them away near the water pump. I ran the main cable harness into the back of the intake manifold and under towards the front. Got each bank coil connector just proud, and the MAP sensor wire. Do i need to hook up the blue map sensor vaccum line, as well as the MAP sensor in the intake manifold?

I also am thinking that if i have to drill and tap a Manifold Air Temp Sensor into the intake , would behind the throttle body be the best place?









The Alternator on this motor has a two prong tab, and i dont think i got the connector for it... or i lost it. The holley harness doesnt have anything for the alternator, can i just replace the stock 79 two prong ( clear ) plug, with a plug fit for the Alternator on this new motor?


I have to wire in a relay for the fans, and one for the fuel pump. so i got a little generic box of 6 relay and fuse slots. Will be nice to have the space for some extras. I still have to wire in the starter and basically everything. Im taking a lesson in patience and im trying to just make it clean ... which is hard for me with wiring, as it gets caught on.. every little single....fu.. thing... I still have a ways to go but im starting to get a good layout down.

 

[bix]

Ive been reading in forums of guys installed the MAT sensor in the intake tube as well. Id rather drill a hole in that than in my intake. Only because im not too fancy with taping plastic for threads, and id rather junk a intake tube than an intake manifold. Anyone have any info on this? air temperature should be about the same from the plenum to the intake manifold ?

 

[mrk5]

I don't have any expertise, but I would have said intake tube. I would think the intake itself is probably a little warmer depending on the circumstances.

 

[bix]

I don't have any expertise, but I would have said intake tube. I would think the intake itself is probably a little warmer depending on the circumstances.

Yea me too, its been awhile since ive watched any engine masters but if theres a change in temp, which you are right, there is. Then i think i will place it in the manifold behind the TB. Ive done some more research and that seems to be where it is done the most. It would have been nice to just plug into the MAF sensor, but manifold air temperature is probably much more valuable in terms of tuning.


Picked away at some more wiring, The stock starter cable wasnt long enough, picked up a 65" one which was long enough to tuck under the engine in the old clips. The stock purple trigger wire for the starter just had to be drilled out a bit as the post is bigger but thats it. Got the grounds hooked up and gave it a bump or two. Didnt even know if the starter worked or not so thats good it turns over and sounds good. The coil harness wont be here for a couple weeks, but thatll give me time to hopefully get the rear end set up when the brackets arrive.

I got the fuse block wired in for the two circuits i have for now. Ill mount it up and test the fans, they came as pusher fans so i had to turn over the blade and reverse th
e wiring. The fan is a Hayden automotive Rapid cool. The temps here never really get hot so i think the one fan will be more than enough.










Is the trans cooler in the rad any good or should i have an external? Not being able to see the capacity of the cooler makes me wonder.. this model 4l60e came behind a 4.3L i think so i dont think its going to last long anyway. Still trying to hunt down a 2005- up 4l60e, even just a core, but the island i live on sucks for this sorta stuff. You cant just wonder into the yards, and pick what you want, they all seem like theyd rather not have your buisness... and expect you to tell them excatly what youre looking for... its a shame, so im just waiting for one to pop up online. A core wouldnt bother me because i do plan on getting one built with a corvette servo, 3-4 shift upgrades and a few other goodies to help it survive.

The holley pcm has a dedicated Power/Ground to isolated battery posts, and then it needs a switched on 12v source (red and white wire) as well for the coil and injectors. Th is wire needs to have a constant 12V source, even during cranking. For this my plan is to use the tan wire at the bulkhead which went to the distributor, which id be very suprised if it didnt have constant 12v while cranking. With the accelerator cable gone there is a nice hole in the firewall for the tach wire ( blue and white) and for the tan wire that will get spliced into the 12v ECM power in the dash and out of the engine bay.

Im just wrapping wires up for now until i know for sure 100% what i need or not. Also got some -6AN fittings for the tranny cooler lines. I have enough scrap from the fuel system to run one of them but ill have to order some. Another bonus to using the stock cooler is less braided line...

 

[6872xtc]

I can tell you that with my big block truck with a 700R4 in it, it usually takes quite a while to get the transmission temperature up. It only has the trans cooler in the radiator, however it is an aluminum Northern radiator. Like today, back it out of the garage, drive 10 miles or so to work, and the trans got to 105* or so. I have to screw around for a while working it, usually offroad to get the temperature over 180*, but stop and go traffic for half an hour with the A/C on, can push it up too.

 

[Chevy305]

The factory has the MAT sensor integrated into the MAF sensor. No reason to drill your intake manifold, put it in the air tube.

Your factory MAP sensor should be good by itself for the Holley. I'm not an expert on the Holley system but I believe it's one or the other.

You might need to do some googling on your alternator wiring. It may need some sort of inline resistor in one of the wires to use the '79 style wiring.

 

[bix]

I can tell you that with my big block truck with a 700R4 in it, it usually takes quite a while to get the transmission temperature up. It only has the trans cooler in the radiator, however it is an aluminum Northern radiator. Like today, back it out of the garage, drive 10 miles or so to work, and the trans got to 105* or so. I have to screw around for a while working it, usually offroad to get the temperature over 180*, but stop and go traffic for half an hour with the A/C on, can push it up too.

Thanks for the info. I feel pretty confident just running it through the stock radiator based on what im reading and your info aswell. I figured it might not get too hot without wheeling it and it just being a DD exactly like youre describing.

I did want to run a trans temp gauge at some point, but ill wait til i have less things to worry about first. I dont have AC so...... hopefully traffic jams will be better ?

The factory has the MAT sensor integrated into the MAF sensor. No reason to drill your intake manifold, put it in the air tube.

Your factory MAP sensor should be good by itself for the Holley. I'm not an expert on the Holley system but I believe it's one or the other.

You might need to do some googling on your alternator wiring. It may need some sort of inline resistor in one of the wires to use the '79 style wiring.

Ahh okay gotcha. I was a tad confused because when looking up MAT sensors they arent located on nearly every truck and the stock locations on MAT/IAC moves around. I dont have the most slack in the harness up front, so unless i cut the holley harness( which im not going to do ) the sensor will be closer to the TB but from what i read thats fine.


The forums ive read are kinda all over the place in terms of the alt so ill keep digging. Apparently its all controlled by the ECM so im not sure if just a single charging wire back to the battery is enough or not. Once i have it running i guess i can mess around with a voltmeter. I do see some guys saying stuff about resistors so thanks for putting that out there.

 

[max 02]

I know nothing about wiring but it looks like your making good progress!

 

[bix]

I know nothing about wiring but it looks like your making good progress!

haha that makes two of us! i just pretend i know what im doing so i dont have a panic attack staring at 12K in parts i dont know how to install

 

[bix]

I ordered up the stock pigtail and some 470 ohm 1/2 watt resistors. Seems like thats what i need to trigger the ALT with a switched 12v source.

 

[bix]

https://www.trifive.com/threads/gen-iv-swap-alternator-wiring.116343/ This link has some good tech info on it about the gen 3 and gen 4 alternators.. figure id share.
Now im thinking maybe what i need to do is different, because i didnt realize the alternators were different.


Once i get the truck running ill be able to do some tests but id much rather have 14.7V all the time than 13.8.. I dont have many accesories buuut..MAW?

 

[bix]

Mounted up the relay box today, i dont know how "waterproof" it will be, as it claims to be.. but itll work for now. Its also starting to look like the Teletubbies got high on jolly ranchers, and wired this thing..

I wired up the fan, the instructions said to flip the blades and reverse the wiring but that seemed odd to me, doing both.. the original wiring was correct. Connected it directly to the trigger wire for the fans ( yellow and grey ) and tucked it away. I ran everything to the alternator post for power. I may run the power for the fan directly to the battery, like @Chevy305 had mentioned earlier as it will be cleaner looking an eliminate a wire going across. I followed the stock path under the column and tucked into that soft clamp.











The stock crossmember was being too much of a pain in terms of routing the exhaust. Picked up this cheap trans adapt mount. Measured off the lower control arms, squared up at 32". The one thing i may have to do is cut some metal shims to put under each foot on either side, because it did lower the trans a couple inches.. Is it fair to assume that it doesnt really matter, except when it comes to the geometry of the driveshaft angle in relation to the differential pinion? I was thinking once i get the rear end dropped and on its weight at ride height and i have to measure for a new driveshaft. Ill play with the driveline angle when i can. I have some scrap aluminum square blocks that may work if need be.

 

[bix]

I ended up ordering an extra set of 6AN trans fittings by accident, but they ended up fitting in the rad cooler so thats a win. I had enough left over line from the fuel system to run both of these cooler lines, and potentially the PS lines as well. The manufacturer of the braided tubing i got said its good up until 3000psi, but im thinking of getting a normal high pressure crimped line , for the feed line atleast..






The spot where i had wanted to mount the computer to , wasnt gonna work out because it was just about 1/2 inch proud of the glovebox closing. I plan on mounting it behind the glovebox on the topside of the firewall, the two 2 inch holes will work and i can hide it all away. For now though while i test all this i just bent up a piece of scrap i had in the vice and mounted it on there.