Cracked the tail housing on the first pass of the year. Looking for probable causes.
1968 Cuda tube chassis car 440/727
1/4" front motor plate, 0.090 mid plate, bolt through urethane trans mount
New 3.5" CM driveshaft, 1350 solid joints, 1" freeplay, same length as old 3" shaft
Ladder bars with coil overs, 1degree pinion angle, so there shouldn't be much movement in the front yoke
4200 two step chip on the trans brake.

Have been running this setup 4 years, last year it broke 2 rods in a violent explosion at the 1/4 mile finish line so I suppose the shock from that could have cracks it.
Just trying to avoid cracking another one as it wasn't a fun ride when the fluid got on the slicks at 135mph