5.2 parts interchange

Aren't the balancers a one piece unit with the serpentine belt pulley? I plan on making the engine look like an LA engine so I'll be using V belts.
I read the magnum 318 is internally balanced like the LA and early 340. Hence the balancer question. Also, the flex plate on the engine has a built on ring gear, no? I want to use my original 727 and converter so couldn't I use the old style LA flex plate?