I just did a bit of research on needle bearings. I think I could, without too much trouble, do my own needle bearing cam conversions. The needle bearings are available with matching hardened inner races. Just a matter of turning down the cam journal, pressing on the race, boring out the cam bearing plate and pressing in the needle bearing.
Right side wouldn't be a problem because it can be supplied with oil from the end, the left side might require an oiling hole be drilled in the sheel of the needle bearing and indexing it with the oil supply hole in the bearing shell when it's pressed in.
I'd have to do a little study of oil flow to make sure that it wouldn't pass too much by the needle bearing instead of feeding the lobes. Think I'll order the parts and practice on an trashed cam.