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Adapt 4.3 TBI to SBC?

Discussion in '40- & 55-Series Tech' started by 78 One owner, Sep 30, 2003.

  1. 78 One owner

    78 One owner

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    I have been told that the TBI on my bearing damaged 4.3 can be installed and modified to power my SBC 350. Any body know for sure?
    Anybody know how well a 4.3 can pull an FJ40?
     
  2. Gumby

    Gumby Supamod Staff Member s-Moderator

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    You can put the 4.3L TBI on the 5.7. I don't know that it would be worth it. You would need to change the injectors which are very expensive and the PROM. You would also need to weld a bung in the exhaust for the O2, weld up a bung for the knock sensor, get a V8 TBI distributor, and get a TBI 350 intake modified for pre-TBI heads. You could get a TBI to carb adapter and use your old intake, but you better hope it has the right holes in the right places for the ECT and IAT sensors. You also need a 12-14 PSI electric fuel pump.
    Much simpler to buy a 350 powered truck or van and take the whole thing out.
    A 4.3L TBI in a 40 would make a hell of a rockcrawler.
     
  3. 78 One owner

    78 One owner

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    Thanks for the input! I wanted to save money and not let a perfectly good TBI waste away in my dead Astrovan. Might as well spend the money rebuilding the 4.3.
    Regarding the 4.3 in an FJ40:
    I have an SBC from a Monte Carlo in mine now and it screams down the highway, gets lousy MPG, and gets by so far except for the quadrapuke flooding out when I crawl too slow and bump into anything or go straight up. Hammerhead doesn't have the same carb or the same prob, but, he thinks flooding problem would go away if I pulled a few more R's as in lower gears.
    Is the 4.3 gonna feel like a puss on the highway? Seems like the TBI would be better at staying lit up, and I need the new gears regardless. Might have a Rockbox budgeted by the end of the month.
    Any more input anyone?
     
  4. Gumby

    Gumby Supamod Staff Member s-Moderator

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    The 4.3L came with as much as 235 hp, although I suspect the one in your Astro was a 191 hp. The 350 monte carlo came with as little as 145 hp. Again, they came with as much as 350.

    so it depends. Either way the 2F had what? 90 hp and weighed easily twice as much as the 4.3.

    I've never driven a 4.3L cruiser so I couldn't say for sure, but I think it would be a neat engine. You could solve a lot of driveline issues and weight problems with that little motor.
     
  5. 78 One owner

    78 One owner

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    At one time the 4.3 looked like the solution to my dilemma with my NP 203 doubler kit. Then along came AA with the Rockbox. The whole project came to a screeching halt. Within 30 days I'm trading in my 203 to LC4spdTC adapter kit for a Rockbox from AA. It's gonna cost another $700+ but I recoup $500. I still Eat $700 on the 203 components so there won't be $'s left to play with the 4.3 but this would be the perfect time for it while I have the truck tore up.
    We'll see. Thanks for the input!