1975 carb to tbi swap questions?

I have a 1975 chevy nova I just rebuilt a 1972 350 four bolt main for it and I want to swap the carb for a tbi system. I have a tbi system off of a 87 chevy truck. I have all the components computer and all. Right now I have a eddlebrock intake and eddelbrock 550 on it and was wondering if I could still leave the eddlebrock intake on it and buy the adapter plat and put the tbi system on it. Or will I have to use the intake that came with the tbi system and just drill out the two bolt holes over the exhaust on the intake for the angled bolts to fit on my heads.

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  • 7 years ago
    Favorite Answer

    I dno't necessarily disagree with everyone else, as all have some good points, but there is nothing wrong with TBI.

    Unquestionably (and this is fact, not opinion) your PROM will need to be tuned. No aftermarket PROM will do that. Only one online I know of that offers this sort of service is Brian at tbichips.com. GM fuel injection of ANY sort does not handle modifications without issue, if the PROM is not tuned correctly. The vehicle may feel like it runs ok (or it may not) but if it's running lean, you won't know until you melt a piston.

    Get one of the aftermarket adapters, leave your intake on there now in place. Use the stock '87 fuse panel, as the late 80's fuse panels have many accessory ports to run other items. You MIGHT want to upgrade the ECM from the 1227747 you have, as it's pretty limited, but its up to you. Spend some time over at thirdgen.org (TBI is TBI when it comes to GM, almost zero difference between a truck and car TBI) and gearhead-efi.com to cut your teeth on what is "proper" for converting to TBI.

    I will be converting my car over to multi-port, but I will use the GM TBI throttle body for throttle, IAC, and TPS since it will bolt right up to the intake.

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  • 7 years ago

    Charlie's answer is good. If you stay with the Edelbrock for the intake, everything will match. Not sure what you're doing with the "angled bolts," but the same system will be simpler to make work. My only comment is that a 550 CFM intake might be a good thing and a bad thing- Good because your Nova will be easier to start and run, but bad because at WOT, you may feel a that more air might be better. All in all, I think you'll be happier with that 550 for 99% of the time. LOL, I reckon we all want that extra couple of HP when we're flat out, hey? Good set up. I have a Holley 750 that I'm not pleased with, so maybe a TBI conversion could be a good thing for my old 292 Y-block. ... Take care!

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  • 7 years ago

    Maybe I'm the oddball in the answers here, and this is normally not something I'd suggest to somebody who wants to switch to fuel injection, but that 87 tbi system is not that great of a system to keep up with a 350 if you built it up to any reasonable specs. If you're looking for great driveability, then yeah, that late 80's system will work, but it won't keep up with a properly carb'ed performance built engine.

    If its just for good driveability and if it were me, I'd see if the tbi unit will work on the intake you have, rather than drilling out the bolt holes - that generally guarantees a leak.

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  • 3 years ago

    Go together with a fuel cellphone and drop that historical rusty fuel tank out. The manufacturing facility pump within the tank will flood a carburetor engine. The factory pump in that truck pushes the gasoline strain threw the lines on a tbi setup at 28 to 31 pounds per square inch,that's too much for a carb engine,the pressure on that carb engine will probably be approx 6-9 psi max. Examine around at the tracks and notice the place they want the telephone established Then go kick some asphalt with it.

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  • james
    Lv 5
    7 years ago

    i would put a standard holley carb on it.

    it SHOULD work with the edelbrock & the tbi system, but you get no control over the

    computer....it's going to do what it did for the pickup.

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  • Anonymous
    7 years ago

    i would use eddlebrock intake.

    Please give me the 10 points for best answer!!

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