Just for a visual, here's my tub with 650-16 tires and 3 1/2" Drop Axle up front, and 700-17s and the stock A spring out back... ...and the same but with the Model T spring minus the second-to-largest leaf in back... ...It is a small but noticeable drop.
I used a T spring under my A bone. It did require some work. Firstly I had the main leaf shortened a tiny bit and the eyes re-rolled as the spring was bit wide for my diff and the shackles sat at a steep angle. After the shortening the shackles sit at a nice 45 degree angle. This may or may not matter in your case as my spring perches had been welded on. Next we machined up a set of spacers on the lathe to accommodate the difference in spring width when using the stock A shackles. I also had a set of brass spring bushings pressed in at the spring shop which we reamed to fit the A shackles. Then we milled up a small pair of spacers/spring pads that where rosette welded into the rear crossmember under the U bolts to correct the difference in spring and crossmember arcs and afford a nice solid place for the spring to rest inside the crossmember and bolt up nice and snug as it should. Lastly I used a set of stock Model T 2" spring retaining pads on the U bolts as they had a provision to hold the spring centred and the correct angle to fit nicely on the spring and worked perfectly with the Model A U bolts
I'm getting ready to lower the back of my roadster and have been thinking of a t spring. Which one do you use? I see a bunch of different spring packs listed for the t that are different number of leaves. Do you just use whatever you can get then remove leaves until you get ur tons it where you want?. The other option I have considered is possibly reverse eyeing my stock a main leaf or purchasing a reverse eye main from a-springs. Then assembling pack with a few less leaves. From what I can tell it should do the same thing. Is my thinking correct on this. Posted using the Full Custom H.A.M.B. App!