Thread: Model A rear susp.

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Welcome to CHR, I am also a "New Guy". I solved this problem by buying a whole Brookville frame with the kickup already in it, but I have worked on other A frames. The spring mounts are directly over the axle in the stock A, but why would you want to keep the weak A rear? If you must keep the closed drive line (again, why?) you could try to find a '40 Ford rear (which is wider) which has the spring mount behind the axle and you could fabricate an extension from the back of the A spring arch to mount the '40 spring. A simple possible answer is to locate a rear spring from an A roadster which was much weaker and flatter than the high arch of the sedan spring. I believe there were originally several different size springs with the roadster the most flat and the sedan with the highest arch. Messing with springs can be dangerous and if one kicks out on you it can break an arm easily, but suppose you had the high arch spring and a roadster spring off the car, you could beef up the roadster spring with one or two of the short leaves from the sedan spring. This might give you 1 1/2" to 2" drop. However most of the aftermarket A springs are the high arch type so I do not know where you can find the flatter roadster spring. In the '50s the '40 rear was the standard answer to this problem. Now I would say if you bought a four-bar kit from one of the aftermarket groups you could use coil-over springs with shocks inside the spring and then set up a fourth lower hole in the spring-shock mount by welding a tab on the bottom of the spring mount. However, my best answer is to convert to an open drive line with an 8" Maverick rear and install a four-bar kit. I would try to use the lowest of the three mounting holes in the four-bar mount first and maybe that is already low enough so you would not have to change the mount at all. Summary: 1) get a flatter spring and install it with care OR 2) go to an open drive with a Maverick rear and install a four-bar to use the lowest hole on the shock mount of the coil-over springs. Another possibility is to make your own triangulated four-bar mount and use a Chevy S-10 truck rear similar to what brianrupnow has shown with pictures for the frame of his A-pickup.

Don Shillady
Retired Scientist/teen rodder