J Model Head on KZ1000 Turbo Build??

Ok Motor Gurus...need some advise...

I just picked up a Rajay turbo for my current build and need some advise on a "J" model head...

My motor as it sits now is a 1075 n/a with nice 10.25:1 (ish) pistons and a stock kz head.

For the turbo I would like to drop the compression some and have been looking at pistons, then I read that a J head would drop the compression a couple points if installed with regular kz pistons...

My thought is that with a J head I would not only drop compression, but also gain some flow...with proper APE conversion of course...

Problem is that I am not sure about the compression drop and if the J head would be to much for a street 1075 turbo...Also, I have read but am not sure that some of the J model heads drop compression (like the GPZ1100)...do they all have larger combustion chambers than an early kz head?

Any thoughts would be much appreciated!

Thanks!

Yes, larger chambers on the J.