1935-40 Ford Composite Leaf Spring Rear Suspension Kit

Easy to install but needs mods

I used this composite leaf spring kit from Speedway as part of a T5 5-speed conversion on my ????_39 Ford. The original banjo rear end was also used with the open driveshaft conversion. The kit is well made and easy to install. I did encounter some problems after completing the conversion. Because the composite spring is thinner that a normal steel spring pack, the kit includes lowering blocks to bring the ride height back to normal. There are also rubber blocks on both sides of the composite spring. The problem is with the lowering blocks. They are hollow in the middle and give very little contact area to the rubber block on the bottom of the lowering block and the spring pad welded to the axle on the top of the lowering block. The surface area on the lowering block is not a good match to the spring pad. After a short time, about 500 miles, the torque of the axle housing under load caused the rubber pad to completely deteriorate and the housing to move changing the pinion angle. There is also wear showing on the top of the lowering block because there is also very little contact with the spring pad (see picture). This is not a race car, the engine is a flathead V8 with less than 150 HP and the load is always conservative, no burnouts!. To fix the problem, I made steel plates out of .0625 flat stock and placed them on both the bottom and top of the lowering block. This gives it a full flat contact area against both the axle spring pad and the rubber pad against the composite spring. The rubber pads (upper only, lowers OK) were replaced with solid rubber Ford body mounts of the same size. Speedway should contact the vendor of the product and see if kit modifications are in order.