Re:Piston ID Gurus. SOHC SRP's. Pics N Prescision Measurments
 

or people with warped heads.

Re:Piston ID Gurus. SOHC SRP's. Pics N Prescision Measurments
 

back to the pistons,they look like stock replacements.

Re:Piston ID Gurus. SOHC SRP's. Pics N Prescision Measurments
 

Ya well based off the info Ive gotten from JE tech and some posts I found by the original buyer, they are either the 9:1's or 10.5:1's

He bought them for a boost application D16a6 aswell so Im gonna pray that they are 9:1

BTW- Installing sprial locks >:(, ------- so hard, kinked one last night and stopped trying, need to try it with some oil or something

Re:Piston ID Gurus. SOHC SRP's. Pics N Prescision Measurments
 

the high comp d-series pistons should be domed and not dished...you should have low comp pistons there. now the real question is which low comp pistons do you have.
srp makes different ones that all fit d-series, but will yield different comp ratios depending which block/head/gasket you use.
d15--9.0
a6--9.5
a6--8.5
z6--9.0
y7--9.0
y8--9.0
these are all for the applicaple piston in the listed block head gasket combo. i've calculated the z6 9.0 piston in a y7 block, head, gasket combo to come out to 9.4. you should be fine, but you won't know what the exact comp ratio is until you find out which piston it is and run through a comp calculator...don't forget to account for the head milling. you might want to clay/platigauge the pistons to see if the valves hit.

Re:Piston ID Gurus. SOHC SRP's. Pics N Prescision Measurments
 

well the original buyer bought them for an A6 so Im assuming there either the 8.5:1 or the 9.5:1

I was asked to measure the compression height, from the middle of the wrist pin to the top of the piston.... so Ill go do that right now