Just odd how the metal in the frame rail was cut around the bolt location. I've built a few rides before so it looks suspicious.
Cut flanged and fitted ready to stitch it up.
The frame box was cut around the bolt for clearance because of the way the box was installed. Instead of sliding the box all the way into the original frame rail up to the subframe it was left further back to move the axle back. That centers the rear axle in the wheel tubs so taller tires can be used. The result is that the spring box sticks out, and had to be trimmed for clearance. It's probably also a home made spring box, but all the spring box really is in the relocation kits is a piece of square tubing. Compared to the Mopar performance kit there's nothing you couldn't build easily at home. The US Cartool kit is better quality, but again, it wouldn't be hard to replicate. Just take some extra time and metal. The nicest thing about it is that it bolts to the original spring hanger mount so you don't have to worry as much about locating everything properly. But back to your car, there's no strength in the section that's trimmed, you could cut the entire box back so it's flush with the rail. Wouldn't hurt a thing as long as you didn't cut the welds holding it in place.
Your other choice would be to reinstall the spring box as it's supposed to be installed, sliding it forward into the rail up against the crossmember. But if you do that you'll have to shorten the driveshaft if you've got one that works with the current set up.
It may be a home built Caltrac set up, but I don't see any reason it wouldn't work the same. But I'm just going off the pictures. Maybe it's not as pretty, but it looks plenty functional.
