I extended my Model A rpu's frame by 7.5 inches to accommodate a spring-behind '40 rear end (with a Tardel Z at the same time). I am embarr***ed to say that I have just now realized that if you extend the frame-rail length and reconnect the rails to the stock rear crossmember, you have moved the rails closer together - enough that the body-mount holes miss the body holes by as much as 1.2 inches per side. Remedial choices include: redrill the mounting holes in the body to match the frame, widen the rear crossmember at its center, weld tabs to the rails and drill to match the body holes, put in a crossmember that brute-forces the rails apart, or pie-cut the rails about 7.5" from the rear crossmember so the ends can bend back in to meet the crossmember. I don't intend to run fenders or running boards. Advice?
Bummer ! cant widen the rear crossmember in the center as you will loose the shape for the spring to sit in. You could widen it on each end to bring it back to spec, or weld tabs on the frame. Might look better with the wider frame rail spacing!
I've found piecuts & weld to serve. Just don't grind after welding. Did a bit of align tweeking, to make a pair of ASC '32 rails fit and exit the '31 rear where they should.
Should have welded the 7.5" extensions parallel to frame center line, then just added a tab to the outside to pick up the stock rear body mount hole.
Add material to strengthen the new mounting area on the body, drill the holes and run with it. Or, as suggested add onto the crossmember on each side.
Did you give any thought to stepping or notching the rails over the axle? Just curious as to your plans.
Not sure who your asking but for my ch***is, No. With the car near done now and a full spring built it sits with 2-7/8" between the bottom frame rail and top of frame rail, That's with the weight of 22 gallons of gas in the trunk. If needed I can add another leaf to the spring and end up at 3".
Yes, I was asking you P n B, it was not until I reviewed my post that I see it was a poorly directed comment. I have a future project that will probably see something similar to what you have done. I plan to do it this way to lower the rearend, but it did occur to me that I needed to figure out away to not have the axle tubes bottoming out on the underside of the ch***is rails and hence my question/comment. In my case, I was also seeking a softer ride and came to the conclusion that a step in the frame was needed.
Torch and a high lift jack. Heat and spread the rear frame rails ahead of the cross member and bend rails till the bit you added ends up parallel.
In the case of how I did my Frame, if you need a step in the frame to clear the bell's don't use the A rear crossmember. Build one with less arc in where the Spring mounts hence raising the frame rails. Then you may want to Z the rails to get it at chosen ride height. Lot's of ways to get there. It's all about Math and planning ahead.
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