5.9 magnum w/904 or 999 low gear set w/lockup convertor. which cost effective flex plate to use. several choices as follows. atp z-332, b&m 10239, pioneer fra486. is that crankshaft weight you add between flex plate and crank for the 5.9 magnums? so many choices. what is flex plate of choice. i even have a stock mopar one. 5.9 has the 2 pc balancer. the 1 that the pulley bolts on the balancer not the 1 pc cast. tia.