2003 Chevy Express Engine swap- Compatability

EDDYC5659

MEMBER
2003 CHEVROLET EXPRESS
V8
2WD
AUTOMATIC
245,000 MILES

Would like to swap 6.0 engine in 03 Chevy express for a 1998 5.7 replacement engine. Can you tell me if ineed to rprogram the ECM/Computer or will I need the wring harness and computer module that is in this donor vehicle? Also are there any other compatability issues I should be aware of like exhaust system, cooling hoses etc. The donor motor is in a 1998 chevy express van. The existing motor in the 2003 van has overheated and I believe it has a blown head gasket, when it overheated the engine stalled and now the starter will not turn with the ignition key.
The starter will start motor with a jumper switch attached, I was wandering what could haved stopped the starter from functioning with ignition key switch?

1 Reply

RACEFAN966

MECHANIC
5,029 POSTS

Well you could make it work but it will be more work then it is worth. There is way to many changes in injection and fuel pressure and so on. You have to do a complete swap with computer and everything inorder to make this swap and then you will need to wire in the computer from the 98 as the harnesses are different. Lots of work and wiring.