Tab,
I have a '66 and had the same dilemma as you. I'd purchased a couple of saginaw 4-speed to replace the stock three-on-the-tree. 2 immedate issues were the location of the shifter and there was still a new ring and pinion set to be installed to make best use of the 4 speed on the interstate.
Well I found a tranny that took care of both problems. The GM 89MM. Being that it was factory equipment in full-sized bench seat GM trucks it came with the perfect shifter handle. Plus it has .73 overdrive. If you can find one it's money WELL spent. I have yet to install mine, as I'm waiting to finish my 292. chuckthetruck has some cool pics of one on his website.
-ftyler
