What would be the best way to try to figure out the info of an unknown sprint car frame ?? ... both axles are still in it, so just to make sure, I measure from center to center of each for W/B, and from front of motor plate to what point of rear axle (leading edge or center) to determine set-back ?? .. also, there are no markings that I can see anywhere that would determine brand/make of frame, are there tell tale signs to be looking for to help determine (tubing locations, angles, etc)? .. or does it even matter, since I have the driveline and arms, etc to measure off of for replacement? ... this is a downtube frame that appears to be from the late 1990's to 2000 ... thank you

Measure from the front of the rear motor plate to the front of the axle. Assuming the axle is 2-3/4" in diameter where you're measuring, this distance should be 37-5/8" for a 39" car, or 38-5/8" for a 40" car. If you look at either Maxim's or Eagle's websites in the tech area they'll tell you what their respective torsion arm lengths are. You can then determine the length you have by measuring from the center of the rear torsion tube to the center of the rear axle, with the axle positioned properly in the car (centered and on 6" blocks). The arms you have may or may not match to the chassis you have. If you can post photos of the chassis you can probably get more info from others on this site.

Good Luck

Tim Simmons