A new friend on this board sent me his BIN for his '88 350 TPI (I also sent him mine). Comparison revealed several areas of differences:
1) Both spark tables
2) Max Knock Retard
3) All four fuel/air ratio tables
4) Target IAC idle speeds

Some of the differences are quite dramatic. 88's had a little stronger cam, but otherwise are the same as 87's, AFIK. Are there any other differences in the engines that I don't know about? Could these differences simply be refinements / improvements that GM made for the new model year?

I am inclined to believe that the latter is the case. Since the cam I am running is similar to the '88 cam (slightly more duration, a good bit more lift) I am heavily leaning toward using the 88 chip as the baseline in my car and making modifications from that, instead. What do y'all think of that?

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'87 IROC 5.7l TPI - original owner!

 

I've yet to see a newer cal that is worse then an older one. Thou for a specific car that Might happen. For the MAF cars start with the 89 code. Much better, IMO

 

I've seen a number of posts that suggest the same thing, but I don't have the TDF ($6E) for that, and I'm not sure I want to defeat the cold start injector system (I've got it, it works great, why not use it?). Perhaps for now, I'll try the '88 BIN for awhile and see how that works. I might pop for the other TDF later. Thanks.



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'87 IROC 5.7l TPI - original owner!