Glad the lady gave you your money back on that deal, the Regal will look great after a good clean up, congratulations on getting a better deal, and actually getting that SuperCharger!
With any L36, or L67 engines over 100k, I'd suggest testing to see what LIM Gasket it has, it can be done easily with a DVOM, if the Lower Intake Gasket is not the redesigned aluminum framed ones, then I'd suggest having that LIM Gasket changed, as the possibility is strong for hydra-lock to happen if you have the old LIM Nylon 6,6 Gaskets, they are known to fail, especially if the coolant system was not properly maintained.
If the LIM Job needs to be done, at least you'd be servicing your oil, and coolant, so you will know for sure when you'll need to service those things again.
If you have the old style LIM Gasket you could try to keep driving it till you start to notice coolant levels dropping abnormally, although I do not suggest that route, I did that and came close to having my motor hydra-locked, that could have easily made it throw a connecting rod, which would have ruined my motor.
Once these L36'* & L67'* have the LIM job done the motors are really solid motors, as long as you service things that need servicing regularly.