Does anyone know what the thread pitch is on the exhaust manifold studs on a 12A.. I have tried lowes and i even bought pineapple racing exhaust nuts but none of them will fit. I have been trying metric sizes since it is a japanese car.

Are they metric or standard? Your help will be greatly appreciated!!

 

I would assume its metric ad most likely it is an odd size. I also need to know what size it is since I need to replace at least one of mine. I may have extras off my parts motors so let me know how many you need and I may be able to help.

 

I need four of them. I know that they are 10M but the pitch i have no idea. I have tried 10m 1.25 and 1.50 with no luck.. This is the only thing holding my back my project at the moment..

 

They are 10mm x 1.5. If you can't get 1.5 to fit, there is something wrong with your threads.

Do they look crushed or damaged?

 

So are you trying to replace the exhaust studs or the nuts?

 

Im trying to replace the nuts. Yeah the threads are little weird. I bough 10m 1.5 but they start to screw on but then stop and becomes hard to turn. I don't want to crossthread them on there.

 

Time for a tap and die set, can tell you the exact thread pitch and you can run a die over the threads to clean them up.

 

metric thread pitches come in 1.0, 1.25, and 1.5. the 1.25 i dont think is used that often.

 

alrighty I'll try my best thanks guys!

 

Tension bolts and choke **** are 1.0 pitch. Bellhousing to engine and tranny to body are 1.25. Only exhaust studs and front cover bolts are 1.5.

All are 10mm diameter. This is just a brief list off the top of my header. Oh yeah, the alternator long pivot bolt is 10mm x 1.25 too, while the small bracket bolt is 8mm x 1.25.