Best RTV for exhaust manifolds?

#1
Just got my exhaust manifolds back from machine shop. Wanting to bolt on but wanted to ask what rtv have people used that they can vouch for. I was considering 3 different ones. All permatex. High temp red I think is good for 650 degrees, ultra copper is about 700 and they also have a "muffler sealant" rated for 2000. Anyone ever use these or another product they can recommend? And before anyone tells me to use gaskets, I can't. Motor is a 78 and they don't make any performance gaskets for this motor. Just ones that have a reputation for blowing out which is why I am going gasketless and had manifolds machined.
 
#3
Ultra copper and have the mating surface smooth then use even torque to tighten them down.

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earlbrown

runs with scissors
#11
Use whatever silicone/RTV you have that hasn't solidified yet. It's not going to matter.

The end result comes from the actual application, not what color dye the goop has in it.