You can still buy new/remain 647 for $150-200 Any one know or tried to see if a 647 ECU will work in place of a 165ecm. The 647 ran the 1992 2.5l 4 cly the 165 ran the same engine till 1991. 647 plugs and prom locations are identical to the 165

 

Have you tried the 16156647 in place of the 165 ?

 

No I haven't. Was seeing if anyone else may of known more about it. I did find a 10 year old post of some one asking about it on a v6 forum but didn't come to any exact answers except this quote
"87-91 truck 2.5s used a 7165, 92-93 used the 6647. the 6647 was also used on 92-94 CPI 4.3 engines. i took a look at the diagrams for the 4.3, only shows 1 injector circuit at D16. the 2.5 applications show the same injector circuit being used.

could open it up and see if two drivers are present or are even possible."

Might just buy one to try for the fun 2 of my local salvage yards have a few of them on the shelf for $50.

 

That sure is cheap to try, pretty sure the 165 uses one injector driver