E31, E88, N47, P90 = Square port

N47, P79 = Round port

Those are just the most common heads from the U.S.

E31, E88, N47, P90 = Square port

N47, P79 = Round port

Those are just the most common heads from the U.S.

You mean:

E31, E88, N42, P90, P90a = Square port

N47, P79 = Round port

Also, if the head is original to the '83 and it is in deed a P90 variety it's going to be a P90a. What's the difference you ask? I'm glad you asked...the P90a has hydrolic lifters. From everything I have ever read you do not want the hydrolic lifters. Do a search on this topic and you should find plenty of reading material to keep you busy for a while.

Also for what it's worth there were two different versions of the E88 head made, I believe that the better version was original to the '71 and '72 cars while the less desireable one came on the '73 cars. Again, do a search on this topic and you'll find more detailed info.

One good resource is Bryan Little's Z Garage site: http://datsunzgarage.com/

Edited June 6, 200915 yr by texasz

after angsting over this for weeks, i've finally decided to just buy a well-rebuilt N42. no fuss, no muss, and i'll never have to worry about it again. thanks for all yall's input. i really appreciate it.

if it comes to buying a new set of pistons, does anyone have any inexpensive recommendations?