Engine Rebuild Parts

[David R.]

Getting ready to overhaul engine for my AA. What brands or suppliers do you use for engine rebuild parts: rings, pistons, valves, guides,rebabbitted rods, etc.,.?
Also, would you grind and re use original valves if all stems measure to specs and none appear burnt or damaged, or are new ones better?
I plan to replace valve springs and install adjustable double lock tappets.
Never done an A engine before. Any experienced input appreciated.
Thanks, David R.