As for the original question...floor clearance...there was about 1/8 to 1/4 inch clearance and I just cut a rectangle cut to match the transmission's profile. Seems it was maybe 2" x 3". Not a lot of extra room but no problems.

I bought a 1.25" tall aluminum spacer piece, drilled a new pivot hole and located the ball 1.25" higher and adapted a look-alike shift rod (look-alike meaning it looks like the old 4 speed shifter). So I have a nice short throw scheme that looks just like original. I did have to make some cardstock shims for the spacer piece. It needed a wee bit of adjustment to shift as smoothly as I wanted. T5 was out of an Astro Van. The boot is one I got many years ago from Patrick Dykes along with a stainless mounting piece that fits around the boot. Close to a copy of the original but more rectangular. On one side of it was engraved "Patrick's". I turned it over and used the blank side.

~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end