The HURST tri-five shifter is universal for ALL the 4-speeds - T-10, Muncie and Saginaw. What IS different is the "Installation Kit" with the shift rods and mounting hardware, sold seperately. I'd say that my shifter sits pretty close to center on the hump in my '57, with a Saginaw-3.11.
The Hurst is a PITA to install, as the stick doesn't unbolt from the shifter body. The stick comes forward 2-1/2 - 3" to clear the bench seat, then curves upward and back. I just kinda guessed where I needed to start cutting the floorboard with a tape measure and a paint stick. I never thought until now to make a cardboard template of the shifter AND STICK to make it less of a guesstimate.
Once I got the shifter in the car, it was just a matter trimming the hole big enough to clear the stick for reverse and the forward gears.
To do it again, I would make a cardboard cut-out of the shifter and stick - at least you can bend it around under the car!
Well worth the effort for the fun of shifting a HURST on a 4-speed!!!
Good Luck, Tim