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New Blazer project plan.

colbystephens

colbystephens

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Well, I'm fed up with my green Blazer for a variety of reasons. So I'm going to start over with a more well defined plan. I'll get into that at a different time. What I'm looking at doing is finding a clean stock rig, '87-'91' and starting from there because of the fuel injection, 700r4, hopefully a 241.

Here's my question: there's a gorgeous rig for sale for a good price, but it has a factory manual trans. I like the manual, but I'm curious about the diffence in fuel economy between an FI 350 with the 700r4 And the FI 350 and the 465. I imagine that the 465 is much more efficient, but is it enough to make fuel economy comparable between the two options? I really want this rig, but i don't want to jump into anything like I've been doing in the past, which has gotten me more trouble than I could handle. :doah: :D

Disclaimer: Please, lets not let this turn into a fuel-economy debate. :) Just curious, assuming all other components are equal, do these two ideas have similar fuel economy?
 
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Right now with my truck, I'm getting around 14 mpg. Thats with a TBI 350 and a 700R4 and 35's and a 4 inch lift and 10 bolts. So, basically stock with a lift and bigger tires. I also put a full exhaust on including headers, which seemed to help a little bit. Just to give you some info on that, maybe a manual guy could help you out with the 465
 
What sort of gears do you have? Is your 14 MPG in town, or is that a highway rating?
 
Colby,

I used to run an SM465 behind a TBI 350 in a 1988 NBS extended cab shortbox C1500 (2wd) The truck originally had a 700r4 in it, and I swapped it to the SM465 myself.

I got around 16 mpg with it when I drove it decently with the automatic, and gained a couple when I switched to manual. I usually got closer to 18 mpg after the swap.

The truck had 3.08 gears and 32" tires on it, so I suspect it was more of the fact that it was more within it's powerband in the 1:1 final gear vs lugging in OD all the time. There may have been some savings in the parasitic losses of the automatic transmission, but I doubt it would have been all that significant.

I wouldn't hesitate to leap on a stock TBI 350 / SM465 / NP241 combo in a K5, be a really stout starting point for your driveline. Just need to swap in some 3/4 or 1 tons and do a mild lift. Its amazing how fast you can get a rig pulled together when you are just swapping parts around from one rig to another.

I think you're on the same page as I am with building a much nicer and more streetable rig this go around... I think it'll be nice to be able to drive my truck without fear of the police always chasing me around or having my teeth shook out and going deaf on the highway :haha:
 
3.73 gears, and thats almost all town driving. I went to Rhode Island a few weeks ago, which was about a 550 mile round trip, and I got around 16.
 
Russell said:
Colby,

I used to run an SM465 behind a TBI 350 in a 1988 NBS extended cab shortbox C1500 (2wd) The truck originally had a 700r4 in it, and I swapped it to the SM465 myself.

I got around 16 mpg with it when I drove it decently with the automatic, and gained a couple when I switched to manual. I usually got closer to 18 mpg after the swap.

The truck had 3.08 gears and 32" tires on it, so I suspect it was more of the fact that it was more within it's powerband in the 1:1 final gear vs lugging in OD all the time. There may have been some savings in the parasitic losses of the automatic transmission, but I doubt it would have been all that significant.

I wouldn't hesitate to leap on a stock TBI 350 / SM465 / NP241 combo in a K5, be a really stout starting point for your driveline. Just need to swap in some 3/4 or 1 tons and do a mild lift. Its amazing how fast you can get a rig pulled together when you are just swapping parts around from one rig to another.

I think you're on the same page as I am with building a much nicer and more streetable rig this go around... I think it'll be nice to be able to drive my truck without fear of the police always chasing me around or having my teeth shook out and going deaf on the highway :haha:
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I didn't realize that the 241 came behind a 465. I assumed it was a 295, which made it slightly less desirable to me because of the higher gearing. Now I'm even more interested in it!
 
I've never even heard of an NP295 haha! I am not sure such an animal even exists...

Definitely got an NP241 from 89 up
 
Whoops! :D The truck in question is an '88, so it may or may not have a 241 according to the specs page on the CK5 homepage. I'll have to look. :)
 
Well, plenty of guys wheel 208s just fine, so I imagine I could do it too. Plus, replacements would be cheap! :D
 
and 208s and 89 241s are a direct replacement swap, except for the fine input shaft i assume the later 4 speed/208s had.
 
the 87-91 style k5 is VERY hard to find with a factory 465, if its clean and priced right JUMP ON IT!
 
The truck looks like it did in 1988, and the guy only wants 3500obo. I'm not going to be home for another 10 days tho, so we'll see if it's still around. Trying to be slower and more thoughtful with this build. this rig is a red/white combo, which I love for an exterior, but I'm not a fan of the red interior.

There's another rig, a Gmc thats also very nice w/ 350/700/241 for only $1900. It's not quite as perfect, but either drivetrain seems equal to me, I think. Biggest immediate problem with that one to me is that it doesnt have the slider rear windows. That one's a tan/white, so it won't have the red interior that I'm not crazy about on the other one.
 
Personally I'd go with the manual. Kinda stuck with my 700R4 and while it seems to work fine I just can't make myself trust it. Would KILL for a SM465 but just not in the cards for a long time.

Have heard numerous reports of folks with the 465's being surprised how good the mpg actually was in their truck vs similar trucks with 700R4's. Coworker actually mentioned that the other day about his '87 K5.
 
AJMBLAZER said:
Personally I'd go with the manual. Kinda stuck with my 700R4 and while it seems to work fine I just can't make myself trust it. Would KILL for a SM465 but just not in the cards for a long time.

Have heard numerous reports of folks with the 465's being surprised how good the mpg actually was in their truck vs similar trucks with 700R4's. Coworker actually mentioned that the other day about his '87 K5.
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Depending on how you drive the manual, it should get you better mileage unless you have more than 80% of your driving on highway fast enough to have the OD kick in and stay locked.
Otherwise the maual is equal if not better.
 
I would GUESS that it would be pretty darn close to a wash as far as MPG goes. That said, get it! Hopefully.
 
Highway mileage is what's important to me since it'll be where I rack up most miles. I think that the more inexpensive Jimmy with the auto trans is likely a better fit for me than the super nice red and white manual trans blazer.

Here's the manual trans rig:
3k43m73p75Q45U55P3b6qbd356200825d1a1e.jpg


Here's the auto trans rig:
3ne3k23m55O05Y15W4b6m582df0b6c2271912.jpg
 
Definitely check the auto trans over. Mine's "okay" but soft shifts sometimes and the torque convertor shudders sometimes when at part throttle. Definitely not confidence inspiring. Dunno if I'd wheel with it.
 
It's my trucks evil twin!!!! I hate the tan & gold personally, I can't wait to paint mine. I have had the sliders and the solid windows... Sliders are cool till they leak, then good luck finding the window felts that fit properly. I have the solid windows now. I average in the 15 to 17 mpg range on the hilly 2 lanes here in Pennsylvania in my stock '91 on 31" tires with the automatic ( newer version of the 700r4, I can't remember what they call it). I haven't taken it on a long trip yet to see what I'd get on a long trip. I'd get the newest, well maintained with the least miles you can find, I'd think they should be comparable either way. The less stuff to fix up front = more time and $$$ to build it how you want it!!!
 
colbystephens said:
Biggest immediate problem with that one to me is that it doesnt have the slider rear windows. That one's a tan/white, so it won't have the red interior that I'm not crazy about on the other one.
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If you find some sliders on CL somewhere, you can swap the solids out for sliders. Pretty easy.

Trust me, I learned the expensive way. Though I had to buy a whole top to have the sliders. Well, after receiving the "shipped" topper with sliders, the fiberglass AND glass were damaged. Pulled out the good slider and found another in the junkyard and then installed into my existing topper. No problem at all! Just got to find them. :waytogo:
 
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