When I made my bypasses for the SR-71, I laid them up with a high temp resin from Resin Services (586) 254-6770.
Resin HRT 212
Hardener HT 386-99

No post cure required and it is good to 325 degrees or so. From my understanding it's used by some of the NASCAR guys for some of their layup works.

I liked how the resin worked so well for that, I ended up doing the entire layup of the show plane that everyone has seen out of the same resin. Considering the skin of the black airplane gets to the low 150's in the Midwest summer heat in the sun, now I don't worry about it getting soft. Now the gear on the inside, is a different matter but I don't have to worry about the shell itself.

I used West for my molds and for the prototype, and found West's to be great to work with and very forgiving when mixing. The only 'catch' on the resin from Resin Services, is that it's got to be mixed by weight, very accurately, and very well mixed. I used a small gram scale, and you mix it by weight one part hardener to 3 parts resin.... so for a full batch, I'd pour resin into my mixing cup to 75 grams, then put in hardener until it read 100, then mix well.

It's a tiny bit thinner than West's but works great, and has a bit longer working time that West as well.

I've had probably a handful of wet starts in the bypasses with them and they are still in good shape, so I'm really pleased how it's holding up.

Lance