Engine Build ?

[mud.man.rj]

Look into the valve lift if using stock springs on the Vortec heads, hopefully the springs are being upgraded, will cause bind if to much lift. A 650 is fine for carb and make sure the builder said cam not crank or may want to get someone else to build the engine. Prob just mentioned crank as in stroker and then mentioned the different firing order, all that does is make it idle better and a bit smoother off the bottom end.