welcome to the garage Mark, drop by the DITY or Welcome forum and give us the story, we always like pictures too thumbs_up
the 700R is a good trans for the truck to hit the highway - 2k will be easier on the old timer, but the 235 can run 3k all day, so you should be able to cruise at 70 easy enough .... and yes, the rear should be a 3.90

Bill


Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics