A bigger intake should help with that cam. But will loose power down low.
A bigger carb seems to be in order 650 might not be big enough at max rpm.
A 383 kit will give you some more cubes but i would not tear the motor down to install one. If it was down for repair fine but a good running engine would not have much gain over 350. Now it should give you some more punch across the board. But to answer your question its only the crank andpistons that need replaced stock rods are fine. But i usally buy a externaly balanced kit with crank, rods, balancer, flexplate, pistons, pins. All balanced from the factpry to be drop in ready. Even if i decide to have the kit balanced by a machine shop for high rpm running. At least if its prebalanced it is cheaper at the shop. Also does not add much to the price of the kits. About 800 to 1599 is normal. Eagle or scat both make cheap kits.
What gear are you running the cam might not be happy with tall gears. Probably needs 411 min.
Some dyno tuning of the carb/timing will usally give up a few more ponies.