When I built my last 383 I used studs, as I was turning some big
HP and just thought they would be worth the little extra cost. I
used thread sealer, and no water problems. Had to do a little shaving
of the bolts in some places for headers to work properly. If I were
racing it, I would go with the studs, but that's just my opinion.
Actually I think mine was a 388 instead of 383.