Hey guys. Long story short I got my hands on a 97 cadillac seville. It needs a tiny bit of work but I got a good deal on it. Any way I pulled the valve covers to reseal them. Im worried about the head bolts because Northstar engines from 97 to 99 have weak blocks and the head bolts rip out of the blocks. When I was in there I found that the head bolts are allen head and look quite beefy. Allen head bolts are usualy an aftermarket head bolt. Correct? Ie never seen a GM engine with Allen head head bolts. Let alone ones that are as thick as the ones my engine has. Can anyone varify this? The reason I want to know is because if the bolts where replaced with beefier aftermaket ones the engine will probably be ok seeing as that is the fix for the head bolt issues on these cars. The other fix is putting in timecerts?threadcerts.