ti depend what flywheel you use , you can use either the 10.5" /10,95" with the alum bel & 130 tooth flywheel from 71 up or the 11" with the 143 tooth flywheel & the cast bel used up to 69
Passion makes there own new casting , Brewers has reconditioned ones & possibly there own new casting as well also Keisler has a nice heavier bel but I am not a fan of dealing with Keisler