ENGINE CASTING CODE

L24 (1970 240Z) # E31 (flattop pistons)

L24 ('71-73 240Z) # P30 (flattop pistons)

L26 ('74 260Z) # P30 (flattop pistons)

L28 ('75-80 280Z) # N42 (dished pistons)

L28 ('81-83 280ZX) # F54 (flattop/dished pistons, siamesed cylinders)

1970 through 1976 heads have square exhaust ports (E31, E88, N42)

1977-'83 heads use rounder, diamond shaped exhaust ports (N47, P79)

1981-'83 turbo heads have square exhaust ports (P90,P90a)

If you put those two lists together with information in the link in post #2 http://www.zhome.com/ZCMnL/tech/head.htm you can match up the years of each head with the blocks and get a little more info on each head. Bear in mind that this is for U.S. models. I know the model lineup differed a bit in Australia.

sblake01

your an animal!!!

thanks heapz bro thats made it heapz easyer