It is hard to tell from the pics but I believe Randy may be on to something. The pic of the modified cross member seems to be 'built up' a bit from the stock mounting location.

 

Erik did you do a conversion from the 4L65E to the 4L80E? Also from what I remember the SS's were originally two piece drive shafts to begin with right? Where did you place your front mount? Is your frame the same as mine where the front nearest cross member is 15 inches from the tranny tail shaft? I think since I have a single piece and the frame crossmembers seem to be at different locations it's gonna prove really difficult for me to be able to convert to a 2 piece DS.

 

Nope, one piece.

BTW, I took mine to well over 150 on the dyno oh, about 20 times and I was flinching the whole time

 

Yep on the conversion to the 80E. What changed things so much was stepping from the AWD to 2WD setups...

The mount for the 2 piece is welded on to the "hump" cross member close to the bed / cab junction (where the stock one goes) -- here's a link to some pics for the stock location: https://www.performancetrucks.net/fo...d.php?t=396083 The first picture is looking back from the tail shaft. You can see the front edge of the gas tank on the right hand side.

Turns out, that's almost the perfect place according to the DS engineer. He said you wanted it about 2/5 of the way back on the over all length. Mine was 85 3/8" over all and I put the bolt center line for the carrier bearing at 37" from the tail shaft, leaving the second shaft at 48". The ideal according to the 2.5 rule would be 34 / 51, but dynotech said it was close enough so I ran with it.

 

Well...Looks that the crossmember that was used is the same one that is beneath my fuel pump, ie this one...





But I have a feeling that since I'm a CC and the both of you are EC that my wheelbase (wheel to wheel) is longer and that crossmember won't give me the correct 2/5 or 40/60 that is ideal. Someone correct me if I'm wrong and the wheelbase is in fact the same.