I personally has a issue on the 35/36 axles on a 32 coupe ( Ok on a A-Ford roadster ) so I has been into the more beefy 37/41 axles. I also like the spring hangers on this axles instead had the spring on the bone, but I never did like the 37/41 bones. But been going on/off here I think I might found the answer that fits me :- )) Rolling Bones made it like this, se picture. The moved the bone inboard and that get a real cool ’racy’ look. I has been into cut the 35/36 bone but even on how good it look it did not ’feel’ that was the way to go.
The 35-40 rear end spring perches are the same width as a stock Model T spring. I have actually mounted a Model T spring in front of the rear axle but I had to add some leaves in the spring to make it work.
I has check a 35/36 and its the same perch CC as the 37 axle at between 48-49”. Cool is a T-Ford, but I will use the A spring I has. From what I get both A and T spring will fit. But what got me convinced was how Rolling Bones did that set-up by use the 37/41 bones. To cut a 35/36 bone is never really a good ide, no matter how good the bone itself look.