Tall Paul,
If you're really lucky, you might get away with replacing the freeze plug. However, I'm kind of with Proffit, I think you're more likely looking at replacing the motor. I've not known of very many that got that lucky with just the plug. There seems to be a number of 235's out there if you take the time to look. You might want to place an ad in the Swap section of the site and see what types of responses you get. I ran one looking for a 216 and probably got a half-dozen leads. I've seen several out on E-Bay that seemed pretty reasonable as well.
As far as the transmission, most of these were a Granny 4-speeds, or as you stated, a "stump-puller". My 52 cruises fairly nicely at 50-55 in 4th (with a stock tranny and a 4:10 rear-end) but it races that poor little motor at anything higher than that.
I know that's a little bit different than what you're looking at, but it might give you an idea of what you're looking at.
Good Luck with the truck purchase.
