While someone on the Barn may have an answer for you, you may want to ask over on the sister publication, Jalopy Journal https://www.jalopyjournal.com . I think you will get more answers over there.
In my mind, the only problem would be the routing of the brake rods. You may want to unhook one front rod and move it up 4 inches to see if there is an interference.
I don't think you can go a full 4", but you can get about 2½" using '32-'34 Spring Perches (-pic below). If you can devise a way to stabilize the Front Brake Shaft Housing, then you probably could use them on a 4" drop. Maybe modify a stock perch with a taller mount for the stud??
Look over at the Jalopy journal, I used model a 4" dropped axle, 1932 spindles, 1932 spring perches, and you add an eye for the brake actuator bolt on top of the perch, others on the jalopy journal have added a piece of flat stock for the actuator bolt.
I did a 4 inch drop with 32 spindles, used some aftermarket hot rod style perches that were added to for the brake actuator attachment.
Not really to hard to make work. As others have said Jalopy Journal forms have a lot more info on ways of doing this type of stuff.