4.3 swap
You would have to integrate the '97 PCM into the older vehicle and that is even if it is possible to just do the PCM...
Your truck either has the TBI (round air cleaner) or CPI (large aluminum intake plenum with a black plastic cover and orange 'Vortec' lettering). Either of these fires the injector(s) in what is called a batch fire method where the SCFI (96+) motors use an injector for each cylinder and fire them sequentially. The electronics in your '94 wouldn't know what to do with the SCFI induction/injection system. Also, you would have to modify the exhaust to be able to have the required number of O2 sensors. Then there is the fuel line hook-ups.
You would be better off just using the long block and swapping over your intake and any other components that are different.
Your truck either has the TBI (round air cleaner) or CPI (large aluminum intake plenum with a black plastic cover and orange 'Vortec' lettering). Either of these fires the injector(s) in what is called a batch fire method where the SCFI (96+) motors use an injector for each cylinder and fire them sequentially. The electronics in your '94 wouldn't know what to do with the SCFI induction/injection system. Also, you would have to modify the exhaust to be able to have the required number of O2 sensors. Then there is the fuel line hook-ups.
You would be better off just using the long block and swapping over your intake and any other components that are different.






