727 problems

[ChargerMad]

Hi all,got some probs with the charger again . This time its with the 727, 3 months ago i had the 727 pulled because i had a broken tailshaft .I removed the box and had the box totally rebuilt with tougher clutches , rear spragg  , tf2 shift kit etc, and a new tailshaft .  All looked good but still had slight vibration at 70 plus as before .2 days ago got involved in a tussle with an audi tt on the highway i smashed the pedal down and took off only to look back 300 yards in my mirror and see this audi appear out of a plume of smoke, i knew exactly what id done and criused the car home at 30 .All the gears are still fine but the tailshaft has broken again.  Been told to look at prop balance, rear trans mount and propshaft angle anyone experienced this    dan