Technical Thread sealer

I believe hemi intake and exhaust manifold or header bolts go into the water jacket. what is the best sealer to use on the bolt threads?
same sealer on both? does it need to be high temp? will the use of thread sealer affect torque ratings? what should I use

 

I've always used Permatex Ultra black RTV, but spotted this recently. Maybe better than just RTV, but I've never had an issue using Permatex

https://www.napaonline.com/en/p/NCB1158514

 

Using Teflon pipe dope with PTFE (I think those are letters) is what was recommended by my engine machinist friend who is built many race engines. A particular pipe dope I'm talking about comes in a tube and when you squirt it out it has a little bit of a granular look to it. I've used it on numerous engines and never had a problem. I squirt out some on threads of the bolt and use my finger to smear it into the threads. Mayby I'm just a slacker but I just torque things like I normally would.

Lynn

 

I've always used permatex Teflon thread sealer in a small orange squeeze tube.

I intend to use it unless someone says there's something better

 

Blue Monster always works

 

that's what I started using per a tip from someone on some google search, and I'll never use regular teflon tape again.

 

On my 354, the two front valve cover bolts also go into the water jacket. A bit of black RTV and good gaskets seem to keep everything where it belongs.

 

Many years ago Permatex #2 was all I used. Used to be able to glue a Flathead together pretty good!

 

That’s what I use, works good. I just torque to spec. Using #2 may affect the torque reading slightly but not sure, I’ve never had a leak.
Dan

 

There has been a lot of advancements in sealers over the past couple decades, just like the paints that are called out for being expensive.
The old faithful #2 non-hardening would be the traditional choice.
RTV ends up too solid for my taste.
Teflon tape or liquid would be a good choice.
I like to ask the folks that make the stuff, NOT the marketing dept, the tech dept. You have the big players who each probably make a dozen or more that will work. Example, Permatex
https://www.permatex.com/product-category/thread-compounds/thread-sealants/

 

Permatex liquid Teflon in a tube.

 

Gotta say it, Gary, that thing is gorgeous!