thoughts on this

[taiparacer]

have seen a a standard early a12 with the dizzy on the front with a a10 head out of a cherry on it it has heaps of pep from what the guy has told me everything else is standard what would u gain by doing this cheers

[classicdat]

I would think it is just increased compression. You would probably gain similarly from planing a std a12 head, I don't know if valves are the same size, if a10 is smaller a12 head for the win I'd think.
Never tried it though.

[Bartman]

I'd say Vaughan is right. I don't know what casting the A10's run? They surely would have had the smaller sized valves though?