logic. Statistically, the UD pulley does not cause problems if you look at the numbers out there of people running them putting thousands of miles. Just because some one's engine dies does not necessarily point to the UD pulley.
Arizona'a most powerful 600HP 15 second Z More powerful than a stock TT , slower than an NA
Dynoed 515 rwhp and 420 ft.lbs @ 16psi 89 degrees. 533 rwhp and 450 ft. lbs @19 psi and slipping clutch and heat soaked motor , 85 degrees.