In my experience, 8mm has roughly the same resolution as NTSC/PAL (roughly because film has no "fixed" resolution - it's just a coating of silver halides whose size tends to increase with the ASA speed). 16mm is roughly HD and 35 is 4k.

But even if you do transfer the 8mm or 16mm prints, me thinks they'd be in terrible shape, not to mention the fact that they'd more than likely be pan and scan...YUCK. Although I have come across a few nice 16mm anamorphic prints. I remember finding "They Live!" once. Ooo! Those reds never looked nicer!

(- I've walked a white line my entire life, I'm not about to screw that up.
-White line's in the middle of the road, that's the worst place to drive.)