68 Dart Project

I'm starting my Dart GT project and have two questions that I need help with. The planning is already months deep, with the expectation to complete at least a year away.(probably longer)
The first problem is a much needed "BARE" 360 block. So is it a waste of time searching for the LA 360 (one which is seasoned and can take a rebuild is rare or extinct)... Or just find a 5.9L ? Remember I only need the block, and i can still buy a new 5.9L bare block.
Are they basically the same block with only slight upgrades in the newer 5.9L. (basically its going to be a 408ci. stroker when finished)
The second questions, will I have to do tranny tunnel work to fit a SB 727 under the Dart floor. Remember its a 68.