Anyone no what pistons these are??

[70c10stepside]

I'm trying to figure out the compression of my motor. I know they are flat tops, Supposedly stock crank and rods.. 64cc heads.




^How the motors sounds/revs

Also, while at it, how strong are stock rods/crank being they are cast?? Where should I not rev too?

Few specs of the motor..
.030 over
508 lift, 313 duration cam
Torker 2 intake
750 holley, 1 inch spacer (Clearance issue)
64cc double hump heads
A few specs....

When we rebuilt the motor, we used the same bottom end that the motor has had for a real long time...