If you retorque them a few lbs higher than before, you'll be ok. This will ensure that they are minimally at the same compressed state that they were in before. This may sound strange to you, but we used red loctite on all main and head studs on hundreds of engines with no problems. Just use it on the ends of the studs that screw into the block, and only use oil on the end where the head nuts are. Make sure you have everything ready to go, so you can torque in as many small increments as you can before the loctite cures. But dont stress over it, because even after it does cure, that red can handle a full turn without breaking the water tight seal. And dont EVER use teflon thread sealants. EVER! Teflon tapes and pastes are made to work with air fittings in buildings and on machinery that uses compressed air, with no moisture and especially no oil. Oil breaks the teflon bond faster than you can sneeze. And after the teflon cures, if you try and turn a screw, at all, the teflon ill rip to shreds and become useless. Ive seen permatex market this crap as 600 degree safe sealant for use on engines...dont believe it. Its worthless on an engine where any fluids are involved...especially oils and gasoline and other distillates. Use blue loctite on all fuel line fittings and red on all oil related fittings, studs, bolts, etc. Green loctite has no business on any engine. Its extremely brittle and extremely hard and abrasive.