Okay, I am right in the middle of welding in my replacement cross member tonight. I tired to reuse the formed cross member peices and added a 2x1 tube across the top, but it became too big. It looked like I was going to be infringing on the bucket seat property, so I went and purchase a 3 x 3/8" flat bar to heat, bend and trim up and over the trans. I am trimming the two ends to just under 2" across and 2" in depth, these will slide right down into the cutoff ends of the stock cross member. I will grind and trim until I get a nice tight fit, then heat up the two bend areas, bend to form the tunnel shape I need (I have template made to match to). Then, I will test fit, tack in-place and roll the trans over to test fit, when all is good, I will weld up solid. I reused the sheet metal tunnel, but beat all the inverted bumps out of it to create more room. It welds in nice at the firewall, but only makes it to the cross member barely, after that it becomes difficult and time consumming. Cut pieces of cardboard to fill the slices that are left, transfer to sheet metal, cut, fit and weld inplace. We are running a 6.1 Hemi with stage two chip, so at 480HP they told us we needed to run the 545RFE, so we went with 3:73 posi in an 8-3/4" Mopar.
Good luck
