I just aquired a rebuilt head with the number N42. I checked mine and it is marked F78. My car is a 1983 280ZX. Will the N42 work with my model?

 

that head will increase the comp ratio from 8.3:1 to 10.3, it's a bolt-on part & we have the P79 (just clean up the lettering some more). you'll notice the N42/N47 combustion chamber is large & round. the P79 is deep & heart shaped like modern engines.

but have the valve seats inspected for depression, i think those are bronze & not steel. the N47 has steel seats. all '70-80 Z/ZXs have dished pistons, 81(?)-83 have flat-top