Re: 5 spd manual transmission?
The 5-speed was paired with the 300-6. At least that's what my repair manual indicates. I don't know if it was even a regular production option. I've noticed Ford will do whatever you want if you order enough of them. I even saw a fleet of 300-6 powered 15-pax wagons for sale once, and I know Ford never publicly offered anything smaller than the 351 in that van. Another 1-off option I used to see was the power company bucket vans were an RB van on an EB frame, allowing for a bucket platform without frame extensions, and retaining the stock bumper.
2000 E450 dually V10 wagon