I have a 65 Barracuda with a slant 6 - three on the tree want some transmission/engine advice

[cudamark]

As the title says, I have this car and its working well, and is a very straight driver, but I am considering two paths, and want to ask the mopar experts what path is best. (I am not concerned about numbers matching, etc. just a fun cruiser)

I would be interested in swapping the tranny from a 3 on the tree to either a floor shift or automatic, which path would be easiest to source and get done for that motor. I can do it, but have limited space, so I might source the parts and then either rent the space or have someone do it.

I would not mind keeping the slant six since I know the motor and am not making a hotrod, just a cruiser that is a driver now. The wife will can drive a floor shift stick well, but the non-syncro 3 on the tree is a non-starter for her, so I would not mind making it easier for her, and in traffic frankly.

So would it make more sense to source a 273 auto and rebuild/swap, or just the transimission for a slant six. Just not sure at this point which path has best parts availability and able to work without having to do a ton of mods, and spend 5K.

Thoughts, resources, feedback is welcome.

There's someone selling that exact '65 S6 904 trans on Craig's list right now. He's down in the SoCal area though......Eaglerock

 

[65 Cuda 340]

Back around 1990, I had a 65 Valiant 100, 170 slant with three on the tree. I swapped in a mildly modified 225, also an all synchro 3-speed floor shift from a 70-something Duster. I'm pretty sure I used the original 65 bellhousing. I know I used the 65 flywheel, although I did have to have the center hole bored out to fit the later 225 crank. Also had to cut the floor for linkage clearance, but the trans fit fine. I cut the floor shift hump out of a Duster (maybe the same on the trans came out of, can't remember) and cobbled it to the early A floor pan. Later found an original cast iron early slant six four speed bellhousing, and swapped in a four speed tranny. Now that was a super fun car to drive!

If you can find the parts, either the all synchro three-speed floor shift or the four speed would, I think, be an easier swap than converting to automatic. Also more fun.