A new cam needs new lifters. Period. End of discussion.
On the engine stand problem, there is a quick simple fix that also makes it safer. Get two pieces of 1/2" X 2" steel flat bar about 18" long, and bolt them to the back of the block, then bolt the stand brackets to the flat bar outside of the block perimeter. It widens the footprint of the brackets and makes the whole assembly safer and more stable.
Exhaust: The Fenton cast iron headers are hard to beat. Definitely stay away from tube steel header systems- - - -all they do is raise the underhood temperature, make noise, and blow out gaskets.
Before you invest in somebody's pricey overhaul kit, have your local parts supplier contact Jackie at Internal Engine Parts Warehouse in Nashville. He can put an overhaul kit together at a much lower cost, and most, if not all of it will be brand-name parts. They're wholesale-only, so don't try to deal direct. Obviously, a big box store like Auto Zone won't provide that kind of service- - - -find an independent jobber.
I've already given you my opinion on carburetion. Have fun and stay in touch!
Jerry
