Simon,

First I'll answer your questions from page 2; the A12A is a stock short block so I would use the GX head on the car now or repair the other GX head I have. The head on the car has been milled dowjn significantly and the static compression would be 9-1 on an A12, the other head would be 8.5-1.

The goal it's to keep the car somewhere between just go out and have fun and crush the competition. 160atw would bring me even with the front running cars in my group as far as powe to weight goes. I run two vintage races and 4 track days per year which amounts to 12 hours. I'd like to be able to run no less than 3 seasons (36hrs) but the naively want to go 5 seasons like I did on the A15. So if keeping the motor down around the 140atw mark meant 50-60hrs versus 180ate would need a rebuilds every 12hrs I'd give up the extra power for not having rebuild as often.

Now as for putting pressure on my decision I was actually looking for the feedback you're providing me great information. While I take a good bit of pride in the fact that I'm driving the heels off my car I'd be nice prevent drivers who aren't driving near as well simply motor by on the long straights.

If we do go the turbo route be forewarned I may PM you with questions.