Quote Originally Posted by 53 Chevy5 View Post
are the pumpkins on rear ends cast iron or cast steel?
I searched long and hard for that answer for the 8.8 in the Spyder. There was no sure consensus on several different websites. One fellow said it had been tested and found to have the carbon content of steel (he never produced the report, though), but it sure appears to me to be cast iron or nodular iron. Probably the latter. It also doesn't spark like steel when ground. Cast steel would typically have a much smoother appearance than the surface on the Explorer rear. It also is telling that Ford choose to pin the tubes in rather than weld them. Seems that welding would have been much simpler.

FWIW - I treated it like cast iron when I welded the tubes in. I used nickel rods and preheat. It seemed to weld fine, but without sure info on what it actually is, I wouldn't trust it for anything critical. That's why I made the 3rd link bracket on my rear bolt on.