The '32 shell is a direct bolt-on replacement for the '30-'31 shell. Even the hood will fit as it should. The stock Model 'A' headlight bar will be very close to the '32 insert but does clear. For a highboy, there should not be any need to shorten the '32 shell. All this info is when installing the '32 shell on a Model 'A'.
When mounting the Model 'A' body on the '32 frame (without channeling the body), the shell should still align fine without sectioning it. The Model 'A' body is often channeled about 3/4" in the front to better fit the '32 frame. If this is done, then the shell and radiator is often sectioned about 2" to keep the cowl/hood/shell in better alignment visually.