I've been tasked with running down the stock rev limit on the 94-95 and 96-97 F body LT1 engines. Probably wouldn't hurt to check the Y bodies as well. I found these bins:

http://www.gearhead-efi.com/gearhead-efi/bin/

But there are no masks in there. Another member mentioned I could make a mask but I didn't look into that just yet as the concept of a mask is still a bit foreign to me. The OBDII stuff doesn't use that. If someone could explain that concept as well or point me to a thread that does, that would be very helpful. The other thing I need to run down is what software will let me view the OBDII tunes. EFILive doesn't go back that far. I suppose if I knew what operating systems I was looking for that would make it easier. I'll be doing some searching of my own in the meantime.