I know they use to sell modified original master cylinder brackets that allowed a dual master cylinder to bolt right in the original location. I actually installed one of these back in the 1990's on a 1/2 ton 52 Chevy..... About the only figuring to it was the length of the push rod, which is adjustable anyway. Allowed the use of the stock pedals....
Luckily I made a pattern off it to modify my bracket when I'm ready.....
John
