hey i have a 1988 k5 blazer and it has the throttle body system in it. I was wondering if i can replace that with a carb. Something like a holley 750 or something similar. I also was wondering what i can change to make it run leaner. Right now it runs very rich and the performance is noticable. It gets bogged down at the start. Any suggestions?

 

It's possible that your O2 sensor has started to go and is causing the rich condition. Also, an exhaust leak can cause a rich condition at the cylinders.

As to your question, yes, you can swap out the TBI for pretty much anything available for your engine. I'm assuming that it is a 350 v8. You would need a new intake to fit on a 4-barrel carb as well as probably a change in the fuel supply system as a carb requires a lower fuel pressure than the TBI unit.

Once you have the carb, you can tune it to run leaner when cruising and feed the fire when playing. The TBI unit should run at peak (or close to peak) air-fuel ratio without intervention if all of the sensors are working correctly.

Good Luck!

 

Hey thanks alot! I am betting it is the O2 sensor because the exhaust is cut of.

I have another question. I recently found a 454 with 400 turbo out of a suburban. Would it set up to my '88 blazer or should i just forget about it?

 

You should be able to fit that in there considering that the engine bay in your k5 is the same as that of the Suburban. Is the 454 TBI? What year vehicle is it out of.

Only problem you may have is your gear ratios in your axles cause, IIRC, you have the 700R4 - 4spd overdrive auto and the TH400 is a 3spd auto (no OD). If you have a TH350, then other than moving the trans crossmember back on the frame, it should bolt up without issues. You may have to replace your front springs cause that 454 is HEAVY!!!

You also didn't mention if your truck is 4x4. If it is, and the TH400 isn't out of a 4x4, you'll have to find a tailshaft and adapter plate and probably a 3/4 ton transfer case to bolt up to it to handle the power. And it isn't as simple to do as I just wrote it out to be...

 

The 454 is out of a 87 4x4. The guy that had my blazer before me had the tranny and transfer case rebuilt. The tranny does not have overdrive. How can i tell what kind of tranny it has? I have had some people tell me that a 454 would be too much for my axles and that i should get 3/4 axles. Is that right or are they crazy?

 

It all depends on what you want to do with it. For just driving around, your stock 1/2ton axles should handle it pretty well. If you want to start crawling/offroading, then you'll probably want something stronger. If you don't depend on the vehicle as your sole form of transportation, hold off on the axles until you need them.

Oh and you probably will have to have new driveshafts made up as well.

 

ok thanks alot. I live in iowa and we have mudd races or mud boggs around the state. I am planning on putting it in those races. i still am trying to decide weather the 454 would be better than a 350 with a little tougher cam. I know the 454 would give me more power but i wonder if it would be easyer and cheaper to just stick with the easy 350 and deck it out with aftermarket parts.. Thanks alot for all your info it is very much apprectiated i can tell you really know your stuff on blazers and on engines for that matter.

 

Some pretty great power can be had out of a SBC 350. I built the motor in my Chevelle when I was 14 and the numbers are from an engine dyno I had done when completed. There really isn't anything special in it. I don't even know what cam it has cause an engine builder friend of mine said it had plenty of duration and lift for what I wanted. Other than that, it has 10.5:1 compression pistons, bored 0.030 over, stock crank, 2.02 double hump heads, edlebrock torquer II intake, and a holley 650dp. Oh yeah... A set of hooker headers and true dual exhaust (really need to add a crossover). The peaks were 425ftlbs at 3400rpm and 386hp at 5500rpm.

But, I am having the same BBC/SBC dilema with my Chevelle right now. I am so tempted to buy a RamJet 502 crate motor and tweak on it a bit, but I also have a spare 350 4bolt main block that would make one mean twin turbo motor. They both would be EFI both would cost about the same when completed, and they both would probably have similar power outputs. I'd be saving around 200lbs off the front end of the car with the SBC.

 

wow.... sounds like you have yourself a heck of a car! I would think that the weight would be a big factor... except witht he big block you be able to put more rubber down... and buy new tires once a year haha