I'll second the Hydroboost idea.
I fit one on my 48 between the frame rail and the manual transmission, a 10 speed Roadranger at that, it's about twice as wide as the old 4 speed...

this is not what I did, but the bracket design may give you some ideas, it mounts the booster farther back.
http://www.abspowerbrake.com/4754chevytruck.html
Second picture up from the bottom.

Grigg

Last edited by Grigg; 12/05/2007 11:22 PM.
•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-