sbc question

i got a 87 sbc thats was tbi and i wan tto switch it to carb ive change the manifold, what else needs to be done? ive heard that the rocker/cam configuration is set for tbi and wont work for carb?

 

I have heard that '85 is the cutoff year for an SBC you'd want to put a carb on, but I can't tell you why that is. Maybe that's the last year they were carbeb from teh factory? I wouldn't think that rocker/cam would matter at all though. You might have some re-timing to do, but beyond that I don't know.

 

I have an 88 sbc with 3x2 rochesters on it.

I did nothing special to this that you would not have done to nay other engine. The only thing I see any different is my block was not cast for a mechanical fuel pump.

 

yea mine was blocked off but i was able to put one in

 

i may be wrong but with the right enginuity you could carb just about any engine..ive seen LT-1s that had carbs on them, and ive seen other engines that were once injected engines get converted to carbs. I figure if you can find or make a manifold for it that will accept the carb than you should have no problem. Just that you will have to rid that engine of most of its computer controled ****, and thats not much of a problem eaither.

 

you may have to drill the holes oblong or grind the manifold a bit to get the intake bolts in, I think they are straight up on 87-up instread of perpendicular to the intake face (86 and earlier). or get an intake made to use the new heads with a carb. but there is no difference in the valvetrain to use f.i.

 

yea i got a manifold that came wit adapters for a later style head

 

If you have a mechanical fuel pump boss, intake and older hei dizzy, you should be in business.

 

My block did not even have a hole in the block for a fuel pump push rod.

 

damn that blows mine just have a block off plate, i had to search around junk yards for a rod, luckily i had a accel dizzy so it fired up right away

 

This is a picture of my 88 block ready to go in. I did use early model heads. The fuel pump is a fake. I drilled and tapped the block for the mounting plates. Bought a swap meet fuel pump and milled out the inside of it and removed the foot, used a stainless steel tube with a fitting tigged on one end that goes through the pump to attach the fuel line with a rubber hose on the inlet side, and attaches witha fitting on the outlet side.

Very little work, and looks much better than a block off plate or nothing at all.

 

did u have to modify the block to used early heads?
*****in motor by the way

 

No, I did not. Almost 12,000 miles and no problems!

 

wow

 

Take the center 2 bolt holes on your intake and cut them out to the edge to look like a u. Throw a dizzy in it and an electric fuel pump with a regulator. You will be good to go

 

Exactly what I did. In other words, the 2 center bolt holes on each side are now open slots because of the bolts sitting upright. I actually used a Performer RPM manifold. I also used a HEI dizzy.

The one downside to using the TBI heads is that they have restrictive swirl ports meant for better low to mid range torque and gas mileage as well as lower emissions. They are therefore not good for top end power even when ported.