93 ext cab short box engine swap

[mhau93obs]

Based off my research my truck is somewhat of a Unicorn. I've gone through rpo codes been and done as much research as possible. It's a 93 ext cab gmc sierra with the 4.3 tbi and a factory 4x4 nv4500. My issue lies with the engine. It's sluggish and I'm concerned about towing with it even with the work ive done to it. Ive put in new plugs and wires, the factory tbi unit took a **** so i went to the junkyard and pulled a unit off a 350 and it runs beautifully right now and has an idle right around 650-750. I'd rather have a little more get up and go in general. I'm not looking to do efi. Based off my knowledge with vehicles i'd like to go either carburetor or tbi as that's what I'm most comfortable around. What sbc options would be the best option, 350 or 383? Should I go LS and toss on a carburetor manifold? What all would the swap entail? Any help is appreciated.

 

[evilunclegrimace]

Just to be clear TBI is EFI, A 350 TBI swap would be the simplest in my opinion. You could find all the neccessary parts at a pick n pull.

 

[mhau93obs]

Just to be clear TBI is EFI, A 350 TBI swap would be the simplest in my opinion. You could find all the neccessary parts at a pick n pull.

It is but it isn't at the same time. I don't know why but tbi makes more sense to me in that situation as it's closer to a carburetor in the way it's set up. Now as for the computer do I have to get a new computer or is there a way to use my factory computer?

 

[evilunclegrimace]

It is but it isn't at the same time. I don't know why but tbi makes more sense to me in that situation as it's closer to a carburetor in the way it's set up. Now as for the computer do I have to get a new computer or is there a way to use my factory computer?

NO, it is EFI it just is not multi port EFI. It does not work like a carb it only vagely resembles one. It would be easier to get the ECM from the truck that you get the engine out of as the PROM and MEM-CAL are different for an 8 cylinder engine.