Stuffing fatter meats inside the rear wheelwells of a Tri-Five can be tough when you're using a stock frame with the leaf springs in the stock location. Since designers in those days never had to worry about anything wider than a skinny tire going inside the fenders, having the leaf springs hanging outboard of the frame didn't present an issue. But with modern, wider tires and wheels the norm these days, along with ever increasing horsepower, it's tough to squeeze an 8-10-inch wide tire and wheel package in those wells without using some serious tricks with backspacing to get clearance. And even then, sometimes they still won't fit.
Enter the easy solution … move the springs out of the way. And it's easy thanks to Classic Industries' '55-'57 leaf spring relocation kit, part no. TF500137. This kit gives you all the parts necessary to box in the frame and relocate the leaf springs inline with the framerails, opening up massive amounts of space inside the stock wheelwells for more tire. The kit also allows you to adjust the rear ride height, and lower your Tri-Five's stance in the back with no fuss at all.
We also grabbed a new set of leaf springs from Classic, part no. TF500250. These are stock height springs, but Classic also offers lowering leafs in 1-, 2-, and 3-inch drop heights. One part we won't be installing in this story (but is highly recommend) is Classic's rear shock crossmember conversion, part no. TF500037 (for narrowed rear) to relocate the upper shock mount from the stock body location to a frame mounted crossmember. We'll show you why in the story. We also recommend grabbing a new set of U-bolts, part no. RL7.
1 Here's where we started. Everything in the back of this '55 is stock except for the shocks.
2 You can see here, with a set of fifth-gen Camaro steel wheels in place (see Chevy Classics 2013 for the story on this is done) that the tire comes very close to rubbing on the leaf spring, and we have no further room for more tire and wheel without creating problems.
3 After supporting the rear end with some pole jacks, we started on one side by figuring out where our forward mount would go. We used the bolt hole in the original spring mount as a reference, and the hole on the new forward insert to locate it. As it happened, we had a bit of frame corrosion in this area that needed addressing, and was actually repaired by installing this kit.
4 Once we had the frame marked for the forward mount, we cut out the bottom part of the framerail using a Sawzall, cleaned the inner frame surface, hit it with some weld-through primer, then inserted the front spring box and tacked it in place. We'll finish weld everything later after we're sure it's all lined up properly.
5 With the forward pocket in place, we measured from the center of the lower hole back about 57 inches to the rear of the frame (just before it Y's out) where the factory leaf spring mount is. Then we made a mark on the frame at this length, and cut the old rear spring mount off the frame.
6 With the old mount gone, we set the rear frame insert next to the frame rail, and traced our cutting pattern. We placed it just forward of where the frame Y's out for the bumper mounts.
7 With everything marked, a cutoff wheel was used to remove the inner part of the frame. Then we removed that piece, traced on the inside of the outer frame section, and cut the rest of that off.
8 After the insert was set into the framerail and welded in place, we located our rear spring mount. It will go behind the gas filler neck, with enough space left to hook up the flex hose to the tank.
9 Another reference point we made for locating the rear mount was where the finger points on the lip of the wheelwell. Once we had the mount located in the right spot, we tack welded it in place.
10a Here's how the front and rear spring mounts look welded in place. The forward mount helped repair a section of our frame that had rust damage. It also has two mounting holes pre-drilled, allowing us to adjust ride height. The mounts use Delrin bushings as well, which drastically reduce deflection under load.
10b Here's how the front and rear spring mounts look welded in place. The forward mount helped repair a section of our frame that had rust damage. It also has two mounting holes pre-drilled, allowing us to adjust ride height. The mounts use Delrin bushings as well, which drastically reduce deflection under load.
11 Now the fun part: relocating the leaf spring perches on our rearend housing. The reason why we left the rear in place and didn't touch the other side was so we could maintain our correct rearend location. First we bolted up the new leaf spring, then set the new perch (part of the Classic Industries kit) in place on top of the spring, then slowly lowered the rearend down until the axle tube was resting on the spring perch.
12 Once the perch was secured, we bolted up the rear to the leaf spring with our original U-bolts, and tacked the perch in place on the tube. When welding on the axle tubes, you want don't want to hit them too hard with the welder at once. The constant heat will warp the tubes.
13 One thing we forgot to mention earlier was removal of the spare tire well. Leaving it in place makes it impossible to install the new rear leaf mount and shackle. It can be reinstalled later after the springs are mounted, or you can get a spare tire well delete panel from Classic Industries, part no. TF4000792, that will cover this hole.
14 With the other side now done, here's how it looked overall, before we went back and cleaned everything up and blasted it with some fresh chassis paint.
15 Thanks to moving the leaf springs, look at all this space we opened up! We can easily fit another 4-5 inches of tire inside our wheelwells, not only giving us more tire and wheel setups to choose from, but also negates having to perform radiusing or mods to the wheel opening for tire/wheel fitment. Combine this with a mini-tub kit, and you've got a serious amount of space for tire.