I cracked open a 165 ECM and found AUM on the chip, was wondering what bin to start with to tune.

Any help would be greatly appreciated.

1227165 ECM, car is an 87, engine is a 350

 

I guess what I really could use is what bin should I tune with, I dont know what mask it uses.

 

Try the bin search engine in the tuning guide (sticky)
AUM come up as 86'
search on the different items till you find one that is close or matches exactly.

 

AUM, thats it, says it on the chip and the tag on the outside of the ECM.

 

YAY i found it, AUM is right... but i still dont know what the mask is.

 

The bin at the bottom right corner of the results box indicates "32"
that would be it if I'm not mistaken.
download it and use that to start with since it is what your car is running on now.
Open it with TunerPro (using a $32 xdf) and confirm it to be sure.

Oops, you need to add a few cube huh ?
That is a 305 bin.
Keep running through the search using the 165 ECM and look for L98 engine.
that will give you the options you are looking for.
Maybe ABWN ??
Searched by "L98" then about halfway down for the"FB" usages that should match your wiring.
Try to find the newest released program with the trans and rear gears that are closest to your setup.