I put one in my 64.
I now have a 350 with a 77R4.
Mine was a 3 speed to start with so I needed a new transmission mount. As well you will need to shorten the drive shaft.
Add a new brake switch. One that will work the brake lights on when you push the peddle and also remove the power (much like cruise control) to the transmission.
And as stated you must make sure the TV cable is rigged correctly.