I can offer some advice. Don't buy it. It's just too old. You are talking about a pre OBD2 engine before 96. I had a 95 460 and a few problems I had with it were much harder so solve being so old. OBD2 scanners have greatly simplified home troubleshooting and if you're talking about a vehicle that you take off road I recommend staying away from anything older than 96 OR a diesel.
There are other problems with vans that old. You need to sit in one and see if the choking seatbelt design is something you can live with. It's my chief gripe on pre 97 Econolines.
Plus, much older transmission and suspension technology. I owned a two 92 460's and one 95 460 (these were the 7.5's, more power than the 5.8/351) and they were all dogs compared to a 97 or newer Triton 5.4, and nothing even in the same ballpark as a V10.
I would look for a 2000 or newer V10 or most preferrably a 2005 or newer V10 to get the 5r110 tranny. It is a magic combination.
Or you can buy a diesel if you like to work on things. I prefer to drive, not wrench.