Driveshaft clearance at trailing arm cross member

[joel.e]

Does anyone know the drive shaft clearance for the various trailing arm crossmembers. Specifically I'm looking for the value from the top of the frame to the top of the hoop for the driveshaft. If I put a straight edge across the frame at the rear of the stock cross member and measure to the top of the drive shaft hoop, it comes in at about 3/4". Just curious if anyone had other measurements of Porterbuilt, ECE, CPP, etc. which are intended to be used with drops. My trans sits a little high in the back so I need the most clearance possible. Just didn't know if I could get away with buying one or having to modify the stock one.

Thanks