^ that seems like op temp to me. try a cool thermostat, like 160-180 deg, and see what it does. You can always remove it since it's not hard.

 

i zip tied and welded my radiator to my 1991 dodge shadow, i ran a 5th injectors so I could turn the boost up to 20psi. i cut 2 radiator pipes in half and clamped them together. used radiator hose as intercooler piping. jb welded a scooby bov flange to an intercooler pipe so I could run a type rs bov on my shadow (there was a scooby flange already stuck on the bov i got it from whitetegls) that jb weld has held up to 25psi w. no leaks at all.