i have a 94 z28 coupe and want to know if i could ever find out what the build number was?

The only "build number" is the sequential production number. That's the last 6 digits of your VIN. First Camaro built in 1994 was 100001, last one built was 219719. There is no differentiation between V6's and Z28's. Thats covered by the "P" (V6) of "S" (LT1) in the 8th position in the VIN. Only the SS's (starting in 96) were serially numbered by SLP in the form "#328 of 2257" or whatever.