Mechanical Cam

Hey guys im gonna build a 273 and i was thinking of putting a mechanical cam in it i have a edelbrock performer intake idle to 5800 rpm the heads are stock closed chamber, its a forged crank its bored 30 over im gonna run electronic ign with the orange mopar box stock manifolds with a 4 speed in a 66 plymouth valiant its a 68 block do i have to do anything special to the block itself to use a mechanical cam or not im gettin the adjustable rocker arms and pushrods, thanks guys