help with ECM and prom

[Shannen Durphey]

WATCHmeDRV at aol.com wrote:
> 
> I have a 88 Vette with 1227165 it has been upgraded to a 16198259 the prom
> that was in it is ABTR4763 and I had a GM dealer order me a new prom so I
> would have one to play with the programming, I thought it would be the same
> numbers on the proms but the new prom # is ABTR4762. The new prom which is
> supposed to be the same as the old prom at least that's what the dealer told
> me, runs better than the old prom. I am lost has anyone worked with this PROM
> or do you know anything about the prom #'s. The new prom runs fine I'd just
> like to change the temp settings. There was someone here that had mastertune
> for an 87 Vette with the 4+3 trans as for as I know it is the same as my 88
> with the 4+3 trans. Would you send me a file to try from the 87. I run a 160
> stat. some the fans at on at 185 and off at 175 is good.
> thanks
> AMERSON

Do you have the bill handy?  The part no. for ABTR/4763 is 16074762. 
I can't find a listing for ABTR/4762, but it's not too unusual to get
a prom with numbers that don't quite match up.  See if the part they
ordered has the same part # as your old one.

The 16074762 calibration was released to cure poor idle stability and
cold engine tip in problems, and is actually shown as an 87
calibration in the bulletin, but lists as an 88 calibration
elsewhere.  GM documentation is completely accurate, unless
cross-checked with itself. : )
Shannen