Definitely weld the perches. 55 chevy small block four speed. It hooked hard on a launch, broke the welds at the axle tubes, spun the nose of the diff up and yanked the drive shaft out of the back of the trans. Ruined the driveshaft, beat the floor up, and scared the crap out of me. If you've spent anytime at the drags you will have seen the same failure on a leaf spring car, and it doesn't even have to be a quick car.
John
