small block fresh up

If you dont already have the 10 to 1 dome top pistons for the .030 over bore you can spend 600 bucks right there. Best advise I can give is forget headers.
Dakota exhaust manifolds and duals will give you better flow than the stock manifolds and a little more hp. I'd poke a new oil pump in it while its out and drop electronic ignition in it also. Tune and tweak to as good as 273 /2brl gets and let it be.
I'm sticking with stock 273 also. If I wanted a rubber burning ,neck snaping, hotrod I'd replace everything from the radiater cap down and back to the rear end. That is pennywise and dollar foolish in my opinion.