What do you guys like for sealing metal NPT threads into plastic intake manifolds that you have tapped to make them leak proof? Blue Monster? Permatex 80632?
What about for the 3 socket head cap screws under the diaphragm that are prone to leaking in certain wastegates? Loctite 592?
For the NPT threads that go into pressure blocks? Loctite 592?

All lines in the image below are 1/4" nylon tubing, using push lock fittings with the exception of the AN lines which are marked.
I want to run a dedicated vacuum to the blow off valves, dedicated vac to the FPR also.
The LS3 intake has a 5/16 evap port which is perfect for a 5/16 hose to 1/4 push lock conversion using a parker 3166 56 08 fitting.
The driver side valve cover I got came with a nice port on the side to run right to a crank case pressure sensor. I believe that one is 3/8.
I'll tap the intake for a 1/4 NPT to 1/4 push lock or a male 4AN to run to the reference line to the FPR.
All this seems to be cleaner than running a manifold block, while not needing to T into the brake booster line.
I'll be using an aftermarket MAP sensor that is 1/8 NPT using an adapter that goes right into where the LS3 stock MAP was.

Based on my discussions with David at Mightymouse solutions, the built in PVC catch can that he offers routed per the image below should be enough for even a max effort 1200 rwhp setup.
The driver side valve cover happens to have an extra 12AN bung already welded on if the current setup isn't enough and a 2nd catch can needed.
Hoping for 8-11 Hg worth of vac to the bov's so that I can just run the light springs that are already in there and not have to swap them out for heavier springs/shimming.
5 PSI springs in the 44mm wastegates should do it as I'll be running CO2 full time.
Plan is to bench test the WG and BOV for leaks and confirm vac and PSI based on spring ratings.

 

I always use the permatex ptfe thread sealant paste, never any issues no matter the material it's screwing into

 

Thank you for the response. I heard that Loctite 272 is also pretty good for high temp areas.

 

For gasoline, oil or methanol on TAPERED PIPE THREADS I use Hylomar. It's Blue, and the tube I have is at least 10 years old, and still flows easily.
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1200 Horsepower: I'd VENT ALL Crankcase pressure to atmosphere with 1/2" minimum hose TIMES TWO.

 

Since making that diagram I ordered a dual catch with 2 vents to atmosphere on it can which takes two 10AN ORB fittings, so I replaced them with 10AN ORB to 12AN male fittings and the plan is to run 12AN lines from there to each valve cover.