They should have bottle neck studs, which means you torque them down against the stud. Not sure on the spec. 45# maybe? Just be sure preload on the lifter isn't excessive.
I should have asked for more info. Stock rockers or rollers? I just assumed you were running a adjustable valve train, most do with c8 c9 or doves. Sorry!on a 1968 c8 429 heads with hydrolic cam are these valves set with a lash or touqe or ? . i have not messed with a hyd cam in a long time memory fails me . these heads have studs not bolts thanks for any help , Phil
Stock has the necked down studs so ya have to torque them. FYI, no 429 PI engines in '68. PI engine was 428 from '66 to '70. '71 was 429.this is a all stock 1968 429 PI motor