94 4.3 to 99 5.7
 

Hy I'm new here. I have a 94 short box with a bad 4.3 and just acquired a 99 5.7 from a suburban. can the 5.7 be installed in the 94. I have the harness and ECM. but what issues will I encounter with the harness on the drivers side? will I have to change it? the plug looks different and what about OBD1 and OBD2 issues. anyone done this before? thanks

anyone?

You would need a engine out of a truck between 89 or 96 to do a straight swap into the 94.

Theoretically anything is possible, but like RusyFordLover said, to do a clean and easy swap, you'll need to get an engine from and OBD1 truck.

Technically the 5.7 will most likely bolt up just fine, but you'll need to go through lots of wiring issues. I'm not experienced in this so I can't say for sure, but you'll definitely need to do your research.