How many miles is too much?

Would you be afraid to boost a 125-150k mile Eagle 5.7? Nothing crazy for power expectations, less than the Jeepie on here to start. There's some local ones to me that I think I could get for under a grand.

In my humble opinion, as pretty much nobody:

Ring lands/piston durability should probably be the main concern, over and above the miles.

Bare minimum? Maybe consider opening the ring gaps. If I remember correctly the last one I rebuilt only had something like .013" on the top ring,
and it seems to me that's an awfully tight gap for a boosted application.

I bought my 2011 ram with 300,000 and a bad cam and two broken valve springs, I thought I should stick another low miles engine I had laying around in it and when I eventually tore apart the original engine the bores looked almost new, the bearings looked new, there was no sludge (lots of wal mart oil change recepits) almost no wear on the valve job, I could have stuck a cam and lifters in it and gone another 300,000, since then I have torn down a bunch more and they always look nearly new unless severely overheated or never had oil changes and even those don't really look that bad. The precision the new hemi is built with along with the oil control engineered into them and better oil technology the cams and springs seem to be the only consistent issue I have seen in them even with very high miles. The 08 and back did have rod snapping issues but that was not oil related but apparently some crappy materiel or something.

I've had the most issues with rod bearings... every single one I've had, 5.7s and 6.1s were pulled due to spun rod bearings. I'll never put another one in a vehicle without inspecting them all first.