3rd over CB350T was what I meant =P. My understanding (from seeing a set used first hand) is that the CB350 (twin) pistons are 64mm bore, and have combustion chambers compatible with a stock CB750. 3rd over (0.75) takes you to 64.75mm, which is a negligible amount smaller than a 836kit.
I'd take a set of cyclex pistons over those any day though...because they're $210 for a set and have the nice 10 1/4: 1 CR.
As for the F3 cam, I mean from the 77/78 CB750 F, the one with the bigger heads. I have the two cams in front of me, and the F cam looks nice and aggressive! This would need to be clay checked though, as always when running cams and pistons that aren't designed for each other...you never know if your head has been resurfaced at some point...
I wouldn't shot peen rods, based only on bad experiences with most shot peeing shops (they're far and few inbetween, and by the time you ship a set of rods to someone competent, get the work done, and shipped back you've already justified one third the cost of new rods. The bolts also add about a 3rd...factor in that your time is worth something and you're already over). In the hands of a competent person, shot peening can do wonders for fatigue strength, but under the wrong hands, it's just a pain that'll likely weaken your rods and cost you (due to deformation and stretching of rods).
I am, however, not a professional engine builder, or anything of the sort. I just tinker a LOT.
