1989 to 1995 ecm switch

[Mike Harrington]

I've got a 1989 k3500 with manual transmission and it had the Mark IV 454 but I'm putting a 454 from a 1995 into it. I got the computer and wire harness from the 1995 with hopes of just switching my out the ecm but I see that is not possible. Is there a wire harness adapter that would allow me to just switch the ECM out and run the one from the 1995? Or how hard is it to switch out the entire wire harness or is it just easier to get a new chip burned for the original ecm or will the old chip work for the 1995 engine?

 

[bucket]

The '95 engine should run fine with the original ECM and PROM. Despite being a different generation of 454, the cam and airflow specs are essentially the same between the two.

 

[Mike Harrington]

Bucket...but what about the egr? The 1995 454 has an electronic egr and the 1989 had the regular EGR valve and solenoid. How would I convert the wiring harness to the electronic EGR? Do they make an adapter?

 

[bucket]

Well there I go assuming again. I just assumed that the original intake, tbi, etc were being re-used.

But why not just use the original setup?

 

[Mike Harrington]

The original setup is a crappy intake that is an actual carburator intake with that adapter to a TBI. The new one is an actual TBI intake. I found an adapter that goes from 2 wire to 5 wire for the egr on eBay I just wonder if it will actually work. https://www.ebay.com/itm/262666546281

 

[bucket]

The original setup is a crappy intake that is an actual carburator intake with that adapter to a TBI. The new one is an actual TBI intake. I found an adapter that goes from 2 wire to 5 wire for the egr on eBay I just wonder if it will actually work. https://www.ebay.com/itm/262666546281

Yes, but the TBI specific intake is just as crappy as the older unit with an adapter.

That ebay adapter may work fine. Iirc, the Painless Performance TBI harness comes with the same adapter for use with the later style egr.