broken input shafts (plural!)

[DrJaysBlown5.0Mod]

I have gone through 2 input shafts in the last 2 months on my daily street driven 2000 GT. The problem started immediately after I had the motor rebuilt, which now puts 480 ft lbs of torque and 560 hp to the rears. Still, this should not be happening. The first input shaft was stock, in the original T45? tranny and original bellhousing. The second input shaft was in a brand new T56 with new bellhousing. Both tranny set ups included a Fidanza flywheel, Spec Stage 3 clutch and drag radials. Each time the input shaft broke we notices the pilot bearing was worn out--after only 2-3 weeks of city driving! What are some ideas for what could be wrong and how to test for each particuluar problem? Thanks for the help!

[explicitone]

motor mounts could be bad causing the motor and trans alim. to move wearing out the pilot bushing

???how did break were you racing,were you just beating the snot out of it or were just driving down the road???.......

[46stang]

I would check crankshaft end play. possibly thrust bearing bad causing crank to move around too much! two different trans with same problem seems more likely the flywheel is not aligned corectly or cranshaft end play issue! good luck!
leon

[Jason1320]

Drag radials on a street car? I think you left out an important detail.

[Jason1320]

Originally posted by Jason1320
Drag radials on a street car? I think you left out an important detail.

Nevermind me.....I read radials and thought slicks. It must be close to quittin' time.