definitely should find out if he knows what the balance was on the engine or if it's an internal zero balance or 28 Oz crankshaft so you would match the balancer and flywheel to 28 oz in that case or if it's a 50 Oz balance you would match both that way and most strokers of that are 28 Oz balance in my experience but basically check your part numbers on your balancer and flywheel you may just have one 28 Oz balancer and 50 Oz flywheel or vice versa