Ditto, Cam and adjustable lifters that have a foot larger then 1". Never run old lifters on a new cam unless they have been resurfaced. The over carburation thing is important too. For most modest upgrades in add on hop up parts, A well tuned single 2 barrel will be faster and better driving then a twin 2 barrel set up. IMHO. I ran a well used B engine that came out of a stock BB truck. I pulled the head and pan. checked and adjusted the main and rod bearings. Replaced the stock .040" over pistons with .040" over aftermarket modern style pistons and rings without boring the cylinders (cylinder walls had .010 "belly" in the center). Used a glaze breaker hone to scuff up the cylinder walls. Changed the cam to a pretty aggressive Winfield grind cam from Jim Brierly. New metal timing gears. Installed a Wieand 7.5 : 1 HC head. Ran two 81 Strombergs on a down draft / lakes style intake header set up. drove and raced it A LOT. It lasted 10,000 + miles until it pushed out the Babbitt in the rods. paid $600 for the engine and probably had $3000.00 in the hop up parts. Your results may very. This is what replaced that engine. basically the same set up. but with insert bearings and full oil pressure. .