Does anyone have experience with installing a floor shifter for a 3-speed torque tube transmission? Specifically, I'm looking at the Mr. Gasket 7667A. I've read some about it, but everything I've found has been about transmissions with open drive shaft. Mr. Gasket's web site shows the 7667A as fitting the '51, but I just want to be certain that it won't take a ton of fabrication/modification. Thanks for the help!