[Rick]

Mel,

I converted my 62 sm318 to a "old style" 3 speed + overdrive (from a chevy).
I paid $400 for the unit, and another $350 to have it checked out, repaired and resealed.
This was 7 years ago, the unit has worked flawlessly since. (once I got the bugs worked out)
It is almost a drop in swap, only the rear yoke, needs to be changed.
I have it in a 62 1000 series. With the original 305 & 3.07 rear gears, I get as high as 18 mpg on the freeway (65 mph engine runs 1750 rpm)
Today I have it behind a 401 in the same truck and get the same mileage.

I feel this is the most practical swap you can do. Yes, other transmissions are better, faster shifting, stronger & smoother. But cost wise you cant beat this swap.
Note here: this transmission has handled the torque of my 401 for more than 5 years. However I do not abuse it.

My 2 cents,
Rick Rusconi