I have a 79 C10 2wd with a rebuilt & modified 350, but she still has the original column shifted 3 speed Saginaw. I want to swap to a TH350. The shifter can be column or floor mounted - doesn't matter. My big question is this; do I have to modify the floor where the transmission will be to make room for the TH350? Or can it be left just the way it is? Thanks for any & all info!