[matt17]

im new to this site and iv been wondering.. Can u switch a 2.5 harness with a 4.3 wiring harness by unpugging them at the firewall under the hood and it work right??

 

[HappyPants529]

Why would you need to? Is there some circumstance where you can't get a 2.5 harness?

 

[Mad Max]

This won't work... remember - there are 2 injectors in a 4.3, the 2.5 has only one. That is just a start. The management system is similar in both cases, but the wiring is way different.

Answer,
no,
you can't mix wiring harnesses/ECUs unless you have a degree in computer science and electrical engineering...

Oh, and welcome.