So to help my brother and what not. I ordered a ecm. I did not want to pull out the ecm since I already did at one time and ordered one. When I got it. The number was not the same but upon cross reference. I found that the there was 4 ecms that would work providing you might have to change the rom. So I did that and the truck runs the same as before. But what is the difference between the following.

My truck came with:

BBNT

The chip I got was:

BHRJ

I went ahead and used the BBNT prom since that came with the truck. The ecm had the following numbers.

16196395 & 1616825 the 625 was the on in my truck. But yes I know those will work.

So back to the eprom. Can somebody shine any light on it?

Oh and my truck is a 93 s10 blazer 4.3L with vin w so it has cpi in it. Automatic trans.

Thanks,

Josh