I am plainning to take a 4.3 out and change it with a 350 Chevy?

J

JamesN

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I have a 1995 Chevy W/T 1/2 TON PU and the 4.3 is bad and I bought a 1990 350 engine to put in it. A man said I may have trouble because of the computer don`t match and a few other things.
I need to know what I am getting into because I`m ok when it comes to changing out motors but don`t know about the computers. Is it going to be more trouble than it`s worth? One put a 305 in his and said some gages and A/C don`t work.I need my truck for work,and to tow a trailer with but don`t know how to change computer stuff,HELP PLEASE.Thank You for your help.
 
The computer is not that big a deal as long as the wiring harnesses fit with the swap out motor. The ECM (Engine Control Module) on most GM vehicles is mounted under the dash behind the glove box.

If you have a resistor chip in your ignition key (a black computer chip on the key shaft itself), then you have to know the resistance value (Can be read with an Ohm meter). This is the VATS (Vehicle Anti Theft System) that is also controlled by the ECM computer.

You will need the ECM for the 350 which is about $135. Since you are changing the entire computer, you can't use the old EPROM IC chip for the new computer, so an additional $200 for the chip for the new computer. If you want to take a chance, check the junk yards for a used one. Hopefully you can find a good computer cheap.
 
The computer is not that big a deal as long as the wiring harnesses fit with the swap out motor. The ECM (Engine Control Module) on most GM vehicles is mounted under the dash behind the glove box.

If you have a resistor chip in your ignition key (a black computer chip on the key shaft itself), then you have to know the resistance value (Can be read with an Ohm meter). This is the VATS (Vehicle Anti Theft System) that is also controlled by the ECM computer.

You will need the ECM for the 350 which is about $135. Since you are changing the entire computer, you can't use the old EPROM IC chip for the new computer, so an additional $200 for the chip for the new computer. If you want to take a chance, check the junk yards for a used one. Hopefully you can find a good computer cheap.
 
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