no keyway. there's a engine stop tool that you remove the starter and bolt in place that has teeth that engage with the flywheel to keep it from moving.
arp bolt has a more simple tq spec and is reusable. oem bolt is a one time use, require tighting by angle gauge/torque wrench with that setting. Google will have the specs. it's very very tight. works out to something like 300plus ftlb.
most people buy the arp. I went with oem replacement. looks like they put a lot of effort into that oem bolt. it's got thread sealer/locker on the threads and a under head friction pad. is tightened to a much more than what arp calls for and was like 10$ compared to 60$ arp.
easy way? arp bolt, hit it with the strongest impact you have access to and it will 99% never be an issue. these trucks aren't very ******* balances compared to performance applications. gm needed a spec that would cover any vehicle the engine ended up in. from slow shifting suv to a 500hp ls7 with a manual behind it. those eat oem balancerd by 60k miles and it's more common to hear about the bolt coming loose after a change, where my suv has 160 and the original is still in good shape. low rpm and slow changes in rpm the outside bonded rubber ring seems to last a log time.
