Head Bolt Sealant?

[CZSteve]

I'm re-installing some heads on a SB Chevy. It's been awhile and wondering what type of sealant you'll recommend for the head bolts that will be penetrating the water jacket? Best sealing with the most accurate torque reading?

FYI:
Motor is from a '71 Camaro that I had rebuilt. I'm marinizing it and installing in a I/O boat.

[R Pope]

Never seen a SBC that needed sealant, just clean 'em up and oil lightly. Torque is (supposedly) a function of bolt tension, the drag of the threads are a small part of it.

[73RS]

I've seen quit a few leakers on head bolts and always use a sealer. I use the locktite 242 if I remember the number right. I have seen other types out there but can't recall the name. I personally don't like taking a chance on leaking water into my oil from the headbolts that do penatrate into the water jacket. I also know quit a few folks that have never used any sealant, some end up with leaks while others have never leaked?

[CZSteve]

Picked up some Permatex thread sealant (#56521) @ NAPA.
http://permatex.carshopinc.com/produ...id/42263/56521
I've been under the impression it's best to apply a sealant.
Any down aside from some possible torque readings?

Just finished running a tap through all the holes and going to put the heads back on tomorrow.

[MI2600]

I use Ultra Black RTV and torque to the normal 65lbs.

[1JohnnyO]

Permatex, sorry dont remember the number, but it's white, and has teflon in it. I use this on intake bolts also.