I'm looking at this Porterbuilt trailing arm crossmember.
http://pbfab.com/63-72-trailing-arms...ece-driveshaft
I really like the simplicity and neatness of it. It's adjustable and you can compensate some for wheel center position, and pinion angle. It's probably light too. The price is reasonable and the shipping isn't bad. I'm slightly hesitant as there is a lot less structure there than on a stock crossmember. I will be putting a 6.0 in this truck and will eventually upgrade to LS3 heads and a cam that should put well into the 400's for HP. All of the force required to move the truck is transmitted through these two tubes into the frame. My gut tells me it's strong enough but I'm still slightly hesitant to pull the trigger. Any opinions are appreciated.