...I would think, if the threads are in good shape and the Bolts are Straight, No pitted rust; and they can be brought up to 'Boss 351C' Torque Specs of 125 Ft/Lbs, they could be used over, Indefinitely!
One Might chose to upgrade to 'Grade 8' Bolts, or even, '12 Point Head' Aircraft Bolts. I upgraded to ARP Head Studs, with 'Hex' Nuts and Hardened Washers. And I would Recommend these for Installing All Aluminum Heads!...
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