The gen IV stadium cars were 700lb wet and 64" (1625.4mm) wide and up to 72" (1828.8mm) wheelbase, the SODA long wheelbase cars were +6.5" between the suspension points and +4.5" wider.
The +6.5" added was +2" forward of the B pillar and 4.5" behind it for a longer
Engine compartment to fit the Polaris 440cc Engine, more elbow room for the driver too so width could of been added to the chassis mid-tube. There is an article in Dirt Wheels magazine July 1995 about the Briggsbuilt SODA cars.
The RPM billet transmissions that were used for the SODA cars used no less than 9:1 ratio gear sets and the stadium cars used 7:1 ratio, VW type 4 CV's were used and with an OD of 100mm I think I've worked out the bearings used for the rear bearing carriers are 100x150x24mm 6020-2RS. The rear stud pattern is 6x 5" pcd I'm not sure of the front pcd and the wheel hubs are machined from 7075 T6 aluminum.
Rear tires BFG radial T/A's 205/60-R13 21.75" dia 7" wide, front tires BFG trail masters 175/80-R13 23.5" dia 7" wide, the rear bearing carriers can fit 12" rims over them too. Knowing the tire or rim diameter is useful for scaling off a side view photo.
Steel tubing used for the chassis was 1.25" chromoly and what looks like 0.75" dia tubing for the cross brace and strut brace tube between the front shock mounts. Front spindles used 3/4" uniball size I'm not sure what size the heims are just that they were aluminum and the solid aluminum suspension links would be 7075 T6 with the steel tubing links being 1" dia and 4130 grade.
The widths of the chassis at various tube intersections would be helpful, also lengths of suspension links and chassis mounting layout for the heims. I have a side profile drawing of the briggs chassis mostly figured out it's the width's I'm having issues with then the challenge of the suspension next.
If others have any info to add or spot a mistake please contribute to the thread, cheers