Originally Posted by markz528
Originally Posted by 69 bee
Should i go with grade 8?


No.

To get proper stretch of the bolt, you want to torque the bolt to 75% of proof yield (follow the torque charts). Cast iron can't handle grade 8 torque.





You do know that a lot of the factory bolts were graded bolts right. LOL. Give me a break.

1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time