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4.3 to 5.7 engine swap


drifttruck99
12-15-2007, 06:33 PM
i've heard numerous rumors about a 4.3 using the same components that a 5.7 uses. For future reference what do i need to do to swap my 4.3 with a 5.7 and keep it fuel injected other than the mounts and exhaust? Can i use that same throttle body? Same fuel pump in the tank? Same computer? or do i need to get these from the donor vehicle? About all i know is the 700r4 thats in it now will bolt up and work ok. This isn't something that i wanna do right now, but a definite when the 4.3 kicks the bucket. Any advice will help.:popcorn:

16th hippy
12-29-2007, 04:21 AM
i know it is an old cliche, but if you have enough money, anything will work. but for ease and cheapness, i would highly reccomend getting the FULL wiring harness and computer from donor vehicle.the 4.3(V6) ECM will not work with a 5.7(V8). in essance, a 4.3 is a 5.7 missing 2 cylinders. same bore and stroke. Fuel pump will work if it gives enough flow and pressure, not sure about throttle body, would really depend on the motor, but would probably be better using the one on the 5.7. If you ever decide to do this, we wanna see pics. I know dropping a small block into an s-10 isn't new, but looks cool when done right.

drifttruck99
12-30-2007, 11:45 PM
I was already planning on taking the wiring harness from the donor vehicle. I plan to put pictures up on my myspace page tommorow. Haven't started the project yet but i plan to as soon as it starts getting warm. (my friend has a very small garage and the truck barely fits) I only wanna do slight mods to get a lil extra power but i don't wanna get radical with it yet because it's gotta be a daily driver for a while. So maybe a slightly overstock cam, dual exhaust, and a K&N filter kit. For now i'm gonna use the automatic thats in it (700r4) until i can find a 6 speed. I wasn't even gonna look at this truck because the body wasn't good but it wasn't really, really bad either. It needed a transmission crossmember, rear brakes, and the motor tapped a little bit. But i got a parts truck to go with it that had a good crossmember. (which reminds me if anyone is looking for a good 2.5 with 76,000 original miles on it let me know) i changed the oil, put in the crossmember and a rear universal. this thing runs like a dream. Everything in the front end is tight it doesn't make any abnormal noises. It drives really good, and i was impressed. i got it and the parts truck for 650 bucks. Ayways my myspace url is thirtyover396. send me a message that you replied to me on automotiveforums. becuase i don't always add people i don't know. Hence my profile being private and all.

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