hi i got a 89 300 zx n/a, and i just recently purchased heads that are port and polished and a bigger cam off a 87 turbo model, i belive in order for the heads to fit i have to have a (w) series engine, can anybody tell me where i can tell if mines a (w) series engine . thanks

^well all 87-89 engines were W series, but IDK if n/a's were w series as well, I thought that only turbo engines could be W series...

All late '87s were W series, All 88sand all 89s were W series. The turbo heads were the very same as the N/A Heads for those years. Since you know there arre W series heads on the '89 NA, the question is whether you have W series '87 heads. Just match up the replacement W-series head gaskets to the base of the '87 heads. If all the openings line up, you are looking at W series heads. If there is a distinguishing mark on the W series heads, consult nissan manual. Do you know the production date of the '87 original engine/vehicle? The details of W series heads is found on Z31.com and use search feature for W series. PDFFLyer

All late '87s were W series, All 88sand all 89s were W series. The turbo heads were the very same as the N/A Heads for those years. Since you know there arre W series heads on the '89 NA, the question is whether you have W series '87 heads. Just match up the replacement W-series head gaskets to the base of the '87 heads. If all the openings line up, you are looking at W series heads. If there is a distinguishing mark on the W series heads, consult nissan manual. Do you know the production date of the '87 original engine/vehicle? The details of W series heads is found on Z31.com and use search feature for W series. PDFFLyer