Hi guys, if i were to put an A15 head on an A12, is there a particlur model of A15 head that would work best? the engine is bieng built for strip use only.

I think H89 is the next best thing to a GX/a12t head.

*no shrouding
*kidney chambers
*biger valves then GX aswell

Various Head info

Yes, agreed. The H89 was used on A14s and A15s.

There was also a Nissan competition head with GX-size ports and the A14/A15-size valves, but that would be hard to find.

werent there inlet ports allso extra high? for better aproach angle, witch is the major benefit of the GX head as it dosent hav a water chamber over the port??

H89 head:

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  10112009(002).JPG (29.77 KB)


  H891 1.JPG (68.28 KB)


  H891 2.JPG (76.27 KB)


  H891 4.JPG (29.13 KB)


  H891 5.JPG (28.08 KB)

cool, thanks guys. probably get one of Bige.

heres a H89 on fleebay
head

What about h75 heads? What are there characteristics?

What version of the A12 are you using, & this is important.
If you are using the 1970 to '73 1200 engine, then you will need a modification to use the A15 head to allow oil to reach the rockers.

If you are using a 1974 or later engine with the set-back distributor, then just bolt it on.

H75 heads have open chambers ports are of the low variety I think
don't look as open as the pics above
check my build thread for some average pics of a h75

First post on my new iPod touch what a cool freAking device