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Thread: Can I do this?

  1. #1

    Default Can I do this?

    OK, this is my first post, so be gentle with me. I've searched the forum (with my limited computer skills) and haven't been able to find what I'm looking for. Any help is greatly appreciated. I have a 1995 Chevy 1500 4wd with a 4.3l Vortec engine. Due to some recent, ah, troubles, I'm going to have to replace the engine. I would like to replace it with a small V8 - maybe a 3.8 V8 or whatever is best fit. I tow a 19 ft boat and need a bit more hp - something that won't be terribly bad on gas. Near as I can tell, all Chevy V6 and V8 engines use the same block-to-bell housing bolt pattern pattern. Not sure about the motor mounts, starter or water pump. The exhaust manifolds would need to be replaced, of course. Anyone who could advise me about this stuff would be greatly appreciated. Thanks!

  2. #2


    Hey @zeebrugge Welcome to the site! I've had no experience in engine swaps but there is a lot of experience here...
    Welcome and enjoy!

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  3. #3


    Welcome to the club. I haven't done an engine swap either. But I would like to give a bit of advice on your swap. If you are towing with your truck I would say step up in engine size not down. If gas mileage while towing is what you are worried about I think you would come out ahead with say a 5.3. I don't think the difference in mpg with out a load is that large to give up the HP while towing. I may be wrong with my assumptions but that is my .02. Good luck with whatever you choose and keeps us informed on your which route you go.

  4. #4


    I may be a little off base with this, but here goes, Im sure others may correct me.
    Going from the 4.3V6 to a 5.0V8 or 5.7V8 or other is going to involve more than just the engine block, radiator and manifolds.
    I would think that you are also going to need the matching wire harness, sensors, and assorted computer control modules and accessories for the engine you are installing.
    I can't speak to exactly what the '95's have for electronics on them, but I would think that a V8 would be different than a V6 in that aspect.
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  5. #5


    If you go from a 4.3 to a 5.7, you'll need new manifolds, obviously, and a new distributor. You'll also need to change your fuel injectors. The throttle body is the same, as is the fuel pump. The radiator may or may not be the same. You'll need to measure it and compare it against the listed one for a 5.7L.
    It shouldn't be too awfully hard to do it, though. Both engines use the same sensors and wiring harnesses. You're lucky. A 1996+ model would be much harder.

  6. #6
    Sr. Apprentice cedicol's Avatar
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    Hey ther Zeebrugge. Your from Belgium it has to be. Me to so welcom to the club. To swap the engine i think you are lucky (look post above me). To do it yourself will not be so eassy if you dont have any experians with working on a car. Still i wish you good luck with it.
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  7. #7


    I havent ever done an engine swap in the trucks (yet), but i've done several swaps into different imports. Usually the best bet is to purchase a complete assembly pulled straight from another vehicle. Find one that comes with ECU, harnesses, sensors, accessories (pulleys, compressor, alternator, p/s pump, etc.) and you will be set. As far as transmission mounting goes.. i'm not sure if there are different parts utilized from v6 to v8, but i'd be careful and maybe ask some more questions around the subject that maybe the driveline isn't built to accommodate the higher power/torque of the v8?

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  8. #8


    Ahh 240s love em easiest car on earth to do a motor swap I used to drift a 89 240 had single turbo sr20. Loved that car till I wrecked it
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  9. #9
    Jr. Apprentice Senshi09's Avatar
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    If your looking for power, try to find a totaled caprice with a ls1 in it. Take everything - Motor, wiring harmess, computer and since it would be scrapped it wouldn't be terribly expensive. You might even get a decent deal on it. It should drop right in, should being the key word. Swap out the manifolds for some headers and you will need new motor mounts as well. That should give you the power you want, plus great mpg. It is NOT easy to do and will take you more then a weekend if you're doing it by yourself.

    When in doubt, search google for 4.3 to v8/ls1 swap
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  10. #10


    The 5.7L harness is the same as the 4.3 V6. both use the same TBI setup thru 1995. You will have to lengthen out one of the harness connectors a few inches to reach. You will need to re-chip or swap computers from a V8 truck. The computer that is there presently will run the truck but the rev limiter kicks in too early because it thinks it is still a V6. Over all, nothing too difficult at all. you WILL, however, need a complete engine to swap in and not just a long block unless you already have all of the parts like manifolds, oil pan, valve covers and such.
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