Check all the various places 235s are advertised for sale. The swap meet here, some of the vendors have forums with for sale areas, most the other old truck forums have a for sale area.
Its not unusual someone will be taking out a good 235 to replace with a V-8 and after it sits in the garage unsold for a couple years the price can be very cheap. That could solve your motor problem with very little cash out of pocket.
The rear gears problem is tougher. There is no easy solution. A guy on another board finally found the elusive 4.11 gears and is finding its going to cost an arm and leg to rebuild the rear he has.
My own solution was to replace my rear with a GM 14-bolt with gears I liked better. Other guys have used other axles. I see axles that might work advertised on craigslist all the time in my area, you might find some in yours too.
