100,000 miles? She's still young!
So far as I know, Trade's car (owns Raptor) has 125,000+ miles and it is screaming with the kit he makes at 6 psi. I made some stupid mistakes in the beginning with my own car at 5-8 psi, and it has more than held it's own, and is now approaching the point of screaming as well.. I must say, the resilience of these motors has surprised me a lot during my building/tuning. If I were in your shoes I would supercharge your car, then buy some internals while you enjoy it for a bit. When she blows up or wears out (or the most likely scenario- when you get bored lol) you'll have everything in your garage ready for the internals upgrade that you wanted to do all along anyways