Thanks 66Sub,
I think you're exactly right on the RPMs. On further familiarizing myself with the truck it has a GM 12 bolt rear end and doing the drive shaft/wheel rotation check several times supports a 4.11 ring and pinion ratio strongly.
I have a working 700-R4 from a neighbors wrecked Chevy truck. I would guess I'd have to have the forward drive shaft section shortened(?) to accomodate the additional length over the Saginaw 4 spd. Of course I'll need the kit for the lock out and such. I guess that's right, never done it before.
