Barry Wright rear track width / rear suspension questions

[RW57]

We just picked up an old Barry Wright underrail 2 x 2 chassis with a camaro clip have no idea what model was wondering if anyone might know what the rear track width would be and what length the axle tubes should be. I am going to put it on swing armed 3 link with solid top link 50 inches long I helped a friend do an old shaw like this with 20 in lowers 50 in top link .They took it to a race sat nite and to my amazement it was toting the lf wheel halfway down the straight one lap it actully pulled both front wheels off the ground it has straight trailing arms will we benfit any from the swing arms. The rear coils are in front of housing with jack screws. we are going to use elimnators instead of jack screws has anyone tried anything like this.I also talked to some people who put a 16 in swing arm on left side rr spring on top of housing what are they trying to accomplish by doing this advantages / disadvantages.

[gadirtracer]

The 2x3 Camaro clip 4-bar cars had 34" axles on L&R. Not sure about the, what I'd assume to be an older car, 2x2 rear frames. Oldest 2x3 car I've seen was a '99, I believe.
If it is a BWRC and if it was after he started numbering them, the serial number would be on the inside of the 2x2 j-bar mount.
Good Luck