Summit sells tools to bend the ridges in the ends of the tube from the inside of the tube. I forget what they are called, but they look like a bolt and a nut with 3 small balls in one end.

1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)