8th digit is the engine code. "P" will be an LT1 5.7l, "W" will be a L99 4.3l. This only applies to 94-96 (10th digit would be R,S, or T). You can also check the trunk sticker for the RPO code (LT1 or L99). 1991-1993 B bodies were available with 305 LO3 and 350 LO5's, but not 350 LT1's.