I had a 4" dropped axle in my speedster, but I wanted to retain the original brake set-up and this resulted in an untidy bracket to support the front brake shafts, reduced the lock due to the reduced track and a goose-necked tie rod which proved very unsatisfactory.
I now have a '32 axle with 1/4" spacers at the perch bolts and '32 perch bolts which support the brake shafts in the correct location.
This drops the car 1 1/2" and with I think 4 leaves out of the spring it probably sits a little bit lower, but with an alloy radiator, lightweight hood & body, plus the motor set back 4", there is less weight on the spring anyway.
The rear is a whole different story and would take too long to explain, but after much experimentation it finally working