Example: 2W87Z8100001
1st digit - GM Division
2 = Pontiac
2nd digit - Series Number
S = Base Firebird
T = Esprit
U = Formula
W = Trans Am (75 - 81)
3rd and 4th digit - Body Type
87 = Sport Coupe
5th digit - Engine Code
A = 231 c.i.d, 2-bbl V6 (1978 - 80)
K = 403 c.i.d, 4-bbl V8 (1977 - 79)
L = 350 c.i.d, 4-bbl V8 (1978)
U = 305 c.i.d, 2-bbl V8 (1978)
Z = 400 c.i.d, 4-bbl V8 (1977 - 79)
6th digit - Model Year
8 = 1978
7th digit - Assembly Plant
N = Norwood, Ohio
L = Van Nuys, California
Last 6 digits - Production Number
100001/up
