I don't know what this is but I like the rear suspension. This style would allow me to cut 17" off of the rear of the frame that really serves no purpose except hanging the back of the rear springs. Another option would be making it a "3 springer" using a Model A rear crossmember and spring like many of the early dry lakes racers. The problem with that is the use of Ford parts.
The good thing is I have them.
I also like the Zed frame if it were necessary to drop the driver lower behind the cowl.