Set some rags (aka old tshirt) in the lifter valley before you start scraping the heads, and clearing the inevitable dex junk out of the coolant ports. Clean the threads of the lim bolts well (either a tap, small flat tip, or razor will work), and use a can of brake clean to hit the bolt holes in the heads, q tipping them doesn't hurt either. Coat the bolt threads in some non hardening sealant (I used some plumber type stuff, forget the name). Probably not necessary, but I worked up to the final torque in 3 steps (5, 8, then 11 lb-ft).
Most important part is flushing your coolant out before you start, water in your oil is a lot less harmful than coolant in there, but using a shop vac set to blow on the tstat opening with the lower rad hose removed gets damn near everything out, you shouldn't get a drop in there after doing that.
