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4.3 / 350 swap


steve24
07-13-2003, 12:38 PM
What all would be involved in swapping out a 4.3 V-6 to a 350 V-8 in my 1994 1/2 ton truck? Eng. mounts, trans, radiator, etc.?

Thanks,
Steve

95corsy
08-06-2003, 01:32 AM
theres not too much involved, because the 4.3 is essentially the 350 with 2 cylinders removed.....i belive all the engine mouts and rad., and trans. will all stay the same...ill try to find some info for ya

secretaznman69
08-06-2003, 10:04 PM
I have the same exact truck!!! (listening in)

secretaznman69
08-06-2003, 10:05 PM
and i dont believe the tranny will just bolt up. I knnow you'll need a whole new drive train, new ECU, move the motor mounts (not much though) , im sure you could still use the radiator, and yeah.... thats pretty much it.

95corsy
08-07-2003, 12:22 AM
well the tranny they use in astros will bolt right up...... im not sure if the C/Ks and astros have the same tranny, but i was assuming they do.... heres where i found out about 4.3/350 swapping.....this is about astros, but alot of the info should be the same

steve24
08-07-2003, 03:31 PM
Thanks for the info guys. This truck belongs to my son, and I think he's just about decided to stay with the V-6 a little bit longer. :wink:

95corsy
08-07-2003, 08:52 PM
Originally posted by 95corsy
well the tranny they use in astros will bolt right up...... im not sure if the C/Ks and astros have the same tranny, but i was assuming they do.... heres where i found out about 4.3/350 swapping.....this is about astros, but alot of the info should be the same
i dont know what happened to the link, but its http://www.racecraftconversions.com

wally91vhevrolet
01-27-2009, 08:21 PM
i just put a 350 in my 91 c1500 pickup that had a 4.3. I'm having problems with the sensors (plus all i have is headers and my o2 sensor is not hooked up. Anyway the trans is the same. 4.3 motor is the same just 2 less cyl so everything is compatable (almost everything). Motor mounts have to be replaced. Go buy some for a 350 for your model truck and pull the v6 mounts out. (V6 mounts are located too far back engine bay. Radiator is different on mine. Hoses are different sizes (length of course, and diameter). All sensors seem to be the same. Injectors are different. Prom is different in the CPU. One thing i found out is the brackets for the accessories have a different offset that the v6.

Anyway, with that said, i ordered the new PROM on ebay, and the guy sent me a small one and a big one. I know where the big one goes in the cpu under the metal plate, but the small one? Does anyone know? Now my cpu is acting up. Motor wont crank and im not getting and service engine soon light so i think something messed up with the cpu. cause i dnt have the o2 sensor on there yet (only headers). Anyway can someone help me out?

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