Well, also that the 360 is externally balanced. An aftermarket 360 external-balance flexplate would allow you to run a neutral-balance torque converter, but you would have to run a 360 damper up front. Couldn't use the one from the 273. Would have to run a 360 oil pan, too, but that should fit a 65 Barracuda OK.
A 340 would drop right in, but they are hard to find these days (I'm old enough to remember when they were easy to find in junkyards, but that was a long time ago.)
