TBI to Carb'ed?
 

Hey I recently picked up a '90 dually(old style) and I want to get rid of the TBI crap and convert it to Carb. Is there a specific year intake I need? Or is it like everything else Chevy and anything from anything will work on everything?

Re: TBI to Carb'ed?
 

I've searched and come up with threads talking about changing the engine with one from an older truck but none about just swapping the intake. Any help?

Re: TBI to Carb'ed?
 

I did it, I put a 90's engine in my 86 and then converted it to carb, had to get an inline electric fuel pump because the 90's block doesn't have the opening for one. The center 4 intake bolts go in on a 90* angle instead of the 45 degree on the older engines. So I found an alumin intake off a 70's Camaro and filed the 4 center holes so I could get the bolts in at 90 degrees, that was it tho. Now my 90's engine runs with a carb.
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Re: TBI to Carb'ed?
 

I'm getting ready to swap in a 91 tbi 350 to my 74 3/4 ton snowplow/ wood haulin rig. Im gonna dump the TBI intake and keep my edelbrock carb. All you need is a edelbrock 2104 intake. Its the carb version that bolts to the canted bolt holes on the 88-95 heads.
Im also gonna keep the serpentine setup and ran into a few small issues with power steering and reverse rotation water pump. No biggie, just sourced it from the junk yard.
Also figured out how to dump the ac compressor with out a delete pulley. Just moved the idler pulley and got a shorter belt. Saved like 65 bucks.
Got it all mocked up and gonna put it in in the spring after the snow melts.
Bored 30 over, hyperutectic flattops, new crank, comp Rv cam.
replacing stock 40 year old 350..
Ron

Re: TBI to Carb'ed?
 

Will the heads from a carb'ed truck bolt up to a TBI block? If so I'll probably go that route.

Re: TBI to Carb'ed?
 

yes

Re: TBI to Carb'ed?
 

BTW you can find carb intake manifolds with the proper bolt angle. they are not as easy to find as the older manifold but there out there. it would still be easier than changing heads. also some guys have been known to oblong the 4 center bolt holes on the older manifold and bolt them on.

Re: TBI to Carb'ed?
 

Modifyed plenty of the old style intakes to fit the 86-96 heads just oblong the four holes and use the 86-96 intake gaskets
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Re: TBI to Carb'ed?
 

Changing heads takes me about 10 minutes each, and $60 for some junkyard heads I think I'll go that route. Plus, this truck will be towing around 10,000lbs every weekend so I don't really want un filled holes lol.

Re: TBI to Carb'ed?
 

"junk yard heads" :hmm: I dont know about that one

Re: TBI to Carb'ed?
 

is your 90 a sb or bb?

Re: TBI to Carb'ed?
 

It's a sb.
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Re: TBI to Carb'ed?
 

To do it correctly you will need heads, intake, carb, change the sending units in the gas tank(s) and install a low pressure in-line fuel pump. More than likely, you can fix the FI system cheaper than you can correctly change the truck over to carb.

What is the problem with the current setup?

The most common promblem with early FI is a $18 sensor in the intake that makes the truck hard to start first thing in the day. It takes 2 minutes to change...

Re: TBI to Carb'ed?
 

actually the sbc tbi's are low preasure systems. only 2nd year up ss big block trucks, and 95 454 tbi trucks were the 30 psi fuel systems. im not sure on the vortec engines

Re: TBI to Carb'ed?
 

It's on propane, and it leaks. $1100 to get the propane system re certifiable, no matter which way I go I need a tank/fuel pump.

Re: TBI to Carb'ed?
 

cost me 200$ to do brother, that was for the inline holley red pump. seems to be a reliable pump, no regulator needed it pumps 5-7 psi and it only needs one line the send and return are the same, works great for me, intake was an easy mod too.
just my two cents, I'd do it again.