I can find stock pistons but they are all 12cc dish, which if I go up to 78mm would get the compression to 9.91-1 which would be close enough. I actually ordered a couple from various sources ($10 close outs) but to no avail.

I tried the part numbers for 210 and 310. Basically I'm trying to do this on my usual uber-cheap budget. If I just go as is compression will be 9.37-1,realistically going to 10-1 will probably only bring about 4-5hp but the goal is 100 RWHP (current A12 is about 80).

Of course I should stop dorking around and attempt build a proper motor that is in the 120 RWHP range. Using the cylinder head on the A12 would keep the cost down, maybe as low as $1200-1500......proper pistons being the bulk of it.

Tom