While a highly modified glide might be great for certain drag applications I can't see it being stuffed in a street driven car for daily driving in this age and time. I am in the middle of swapping a turbo 400 into my 71 GMC 3/4 in place of the 350 that decided that it didn't want to in any gear right in the middle of the intersection. Two Major deciding factors. I tow with the truck and had the 400 and know that it is a good one. I think my tape measure tells me that the short shaft 400 is 1-1/2 inches longer than the 350 but don't take my word for it.
Your biggest challenge would be having the driveshaft shortened or finding one the correct length, Or spending the bucks and having a new one made.
With the 3:73 gears I would opt for a built overdrive and enjoy the best of both worlds.