ARP Flexplate to crank bolt kits are the strongest bolts you can get to attach a 8 bolt HEMI crank to flexplate for high horsepower and/or highly stressed applications. Made from 200,000 PSI forged aerospace alloy, these were originally developed for NASCAR winston cup competition. The bolts are fully heat treated prior to thread rolling and machining. Flat 12pt head design ensures no clearance problems during installation. If you have a stroker and/or HEMI engine with aftermarket components, high stall converter, etc... these are must have item. You simply can not put in stronger bolts than these.