So, I have an A front wishbone and pairs of '40 front and rear bones. Could I weld/gusset the ball end of the A wishbone to the middle sections of the '40 front bones....and those to the forged(?) rear ends of the '40 rear bones and have a safe, no bind rear suspension? I would attach the ball end to a crossmember with an aftermarket radius ball cup.
sounds like a good idea to me. but I think you'll still need an upper link or links as the '40 bones wouldn't be strong enough for a truck arm style setup. (weren't they originally used in a torque tube arrangement?)
I'd want more than the 40 forged ends out at the axle but otherwise it should be very strong. The front bones are designed to hold a LOT of weight and stress but the ends you plan to use are marginal as they relied on the torque tube. Why not fab a plate deep into the rear of the bone and double shear it to the housing with additional plate? A torque link could also work to add strength... Its a good idea and its been done before, so with a bit of extra work it would be fine.
There was an artacle in Streetrodder a long time back. They used the ball part of a front set of bones and attached them to the rear set of wishbones. Then they just mounted the front plate(were the ball mounts to) to the back of the X member. You could do that and add the extra brace setup that the Hot Rod works sells. I have my rear set up with stock '46-'48 wishbones that attach to a hiem end that is mounted in it's own crossmember. Hot Rod Works has a setup like mine(copied theres) for later cars and it uses a plate with the heim end attached to the plae that bolts to the back of the X member. I'm building an A-V-8 with a Banjo rearend set up as above. Dutch
Done it with a 48 Ford front wishbone. I used two bottom caps, welded one into the crossmember and bolted the other one on. That crossmember also mounts my master cylinder. Nice ride and no bind.