anyone use a rear seal adaptor?

I've got a low, low mileage Gen VI block that i want to build into a 496 stroker. the one piece rear seal is nice but the cost of the flywheel for a one piece seal crank is pricey so I'm looking at using a MK 4 stroker crank (2 piece) in my gen vi motor with the 100.00 adaptor they sell at summit.
anyone use one of these? any problems you can warn me about?

thanks
charlie

 

They work ok - but there's a cost associated with them as well. I can't imagine the right flywheel costing THAT much more. If it were me I'd just buy the right flywheel.