I installed the ARP kit 218-4703 at factory torque spec (50lbft), but the instructions recommended 90lbft. I emailed ARP and they still recommended 90lbft, but they could not guarantee that the head or block can take it. I am sure I can torque them down to like 70lbft, but I don't know about 90lbft. Then again I used a manual 3/8" torque wrench, it was a bit of a bear, I will borrow my buddies 1/2 Snap-on electronic torque wrench if I go any farther. Anybody know what they should be torqued to?