Since your considering this for your A-body '67 Dart I would suggest you strongly consider a built 200-4R OD trans since it will fit in the A-body trans tunnel without the major surgery required for other OD trannys. The 200-4R offers a .67OD and better 1-2-3 gear spread ratios than a 727.
There are several threads about this trans here on FABO.
I had the one for my '69 Dart built by Extreme Automatics in Amelia, OH (Extreme Automatics 2004R complete units and performance parts.). They offer three different build stages to handle up to 1000HP/750TQ. They also offer a modification to the 200-4R where they machine off the bellhousing and replace it with a bolt-on Reid billet bell. Check 'em out.