Assassin Bars install, New Smith Perch for Assassin bars & Pinion angle

[GTX BROS]

I am getting ready to install Assassin Bars and would like to know what the advantage of using the new Smith spring perch that does not require U-bolts vs. the smaller standard perch that uses the U-Bolts.
Also, I plan on using a negative 2 degree pinion angle in relation to what I read at the Transmission output.
Any help is appreciated.
David

 

[65Fury440]

Wish I had used the new perches when I did my bars.
Not needed but nice touch.

 

[5.7 hemi]

You really should set pinion angle 5-7 degrees on a leaf spring application.