willysmjeeps.com

Would a guy be better off using Permatex 1 (hardening)
or permatex 2 (non-hardening) to seal coolant leaks @
head studs. Both 1 and 2 are mentioned in previous posts.

From the Permatex website:

Permatex® Form-A-Gasket® No. 1 Sealant
Fast-drying, hard-setting sealant designed for sealing rigid materials and flanges, or patching holes and joints where permanent assembly is desired. Temperature range -65°F to 400°F (-54°C to 204°C); resists common shop fluids and fuels.
Suggested Applications: Freeze plugs, threaded connections, manifold gaskets

Permatex® Form-A-Gasket® No. 2 Sealant
Slow-drying, non-hardening sealant designed for sealing cut gaskets and stamped parts. Allows for easy disassembly if required. Temperature range -65°F to 400°F (-54°C to 204°C); resists common shop fluids and fuels. Use where sealing is more important than adhesion.
Suggested Applications: Valve cover gaskets, oil pan gaskets

That bit I highlighted in bold text should answer your question. However, as with all questions in life the manufacturer should know best.

Their contact details are here:
http://www.permatex.com/about_contact.htm

Wbr,
Owen.

Any GM dealer will have head/thread stud sealer in a 4oz can. Dip studs in sealnt & screw in finger tight into block ensuring all threads are @ the deck level [do not torqe the studs by double nutting or any other method].

Permatex tech support recommends neither 1 or 2.
They recommend #59214 hi-temp thread sealant.
Napa Balkamp # 765-2648 (4 mil tube), 765-1155 (50 mil tube).

I used the #59214 high temp thread sealant. Haven't had a problem yet. I also use the same stuff on all my pvc plumbing.

Just a guess but if I were to choose between the hardening & non-hardening I'd go with the non-hardening in the chance it might mess up the threads if you remove the studs. Plus when you re-torque, you need it to be pliable.

Remember you do not torque or retorque head studs. You torque and retorque head nuts on an L134. The stud is not suppose to move during either process so a hardening sealer on the threads is not an issue.

I've used Permatex 1 for 40 years without any problems. Yes there are newer, fancier and more specific products today that even cost more but are not really necessary on this 3/4 century old engine.

I used the Permatex high-temp sealant on my M38 engine studs but after having some leakage issues went back to Permatex #1. The high-temp stuff was a rather thin, almost watery compound and the coarse threads of the studs seemed to me to require a thicker sealant. I'm sure the high temp sealer is good stuff for fine threads but maybe not coarse thread head studs installed finger tight - just my 2 cents.

Thanks for pointing out my error Wes. I have head bolts not studs so the stuff I'm using is probably is not the best. FYI, you have to knead the tube before using the high-temp stuff or it's too runny.