91 K20 454 into 91 Burb 350 swap harness question

[MNorby]

Looking to see if a 454 from a newer body style 1991 K20 would swap into a 1991 square body 350 suburban. Obviously physically it will swap but what about the ecu/harness? Is the harness that same where could just swap ecu and use the burb harness or is there difference enough to need to swap harness as well?

Seems I remember when I added TBI to an old 454 the donor harness for the big block didn't have spark control and I pinned it in.

 

[swettysblazer]

Looking to see if a 454 from a newer body style 1991 K20 would swap into a 1991 square body 350 suburban. Obviously physically it will swap but what about the ecu/harness? Is the harness that same where could just swap ecu and use the burb harness or is there difference enough to need to swap harness as well?

Seems I remember when I added TBI to an old 454 the donor harness for the big block didn't have spark control and I pinned it in.

I swapped a TBI 350 from a 1990 GMT400 into my 1991 K5. Same motor, same fuel injection, etc. and the harness was different. My stock harness runs the motor fine- the firewall bulkhead was different and from what I remember there were some different sensor plugs, but I can't remember.

 

[82355]

A few sensors are different, but you can repin connectors.

Martin