Is your rear end a Ford 9"? If so, I would certainly not think it is the weak link in your drivetrain, especially with the light weight of a Cobra replica, so despite the greater reliability of the Moser/Strange parts , what else do you gain? The Ford 9" is quite reliable in stock form, do you need more?
How about a lighter flywheel? It will allow your engine to rev up more quickly, giving greater acceleration. With 500 FWHP, you can't be hurting for torque in a car this light, so you can give up some of the torque that is gained with the heavy flywheel and let that engine
GO 
!
Cheers!
Dugly
