Torrington bearings can be had with washers that form the hardened races (this is what the Stag uses for the gearbox countershaft).
AFAIK, the "cam button" (between the camshaft & timing cover) is only needed on blocks that have the lifter bores mis-cut, so that one or more of the lifters tries to walk the cam forwards. At least that's what I recall reading in one of the "hot rod" magazines, many years ago. Some engine builder was presenting his conclusion as to why some engines would tear up the inside of the timing cover but most would not. And they weren't particularly reinforcing the cover, just installing the nylon button to touch down first, before the chain did. Not much force involved.
But I don't think you'd ever be able to even measure the resulting improvement, unless you're also converting to a "roller" cam profile with ridiculously high valve accelerations and spring rates. Even then, the improvement would be miniscule IMO; not worth the effort for any scenario I can think of. The folks that get into this sort of thing are racing in classes where these mods are allowed and other mods (like supercharging) are not.
Now, what would really be cool is to implement Variable Valve Timing by moving the camshaft back and forth in the block. Better gas mileage AND better performance !