Yeah. I made a plug to fit the t-stat intake, turned the regulator down to about 20 psi and slowly pressurized it, coolant floor from around that area nearly freely.
Not the whole problem. The intake is a stamped steel gasket. Finnicky under the best circumstances. When i had trouble sealing one it needed sealant everywhere. Might as well put some in you hair to start with, its gonna end up there anyway.