That bus is going to be approximately 30'-35'.
If you do get it, whatever you do, DO NOT
try to turn the engine at all until you have pre-lubed the oil system.
The IHC SV V-8's were about as stout as any engine could hope to be but as in life, everything has an Achilles heel. And for the SV engines is was getting oil to the top end of the engine.
As long as you run them on a regular basis you won't have any problems. But if it has been a long time since it was turned over it is very possible all of the lube oil has drained down and dried out on the cam bearings.
If you don't pre-lube the system you run the real chance of spinning the bearings and ruining them.
This link will take you to a forum where you can learn all you ever wanted to learn about the oiling characteristics of the IHC SV engines. I-4 and SV Engine Non-Oiling Rocker Assembly - IH PARTS AMERICA
As much as I like old 'binders and Loadstar chassis buses I think I would pass on this even at $300.00.
If you are able to restart the engine and get it running you will still have tires, brakes, fuel system, cooling system, et al in renew and refurbish. For what it costs for just a new set of rubber you can get a much newer diesel powered bus that will go at least half again as far if not twice as far on every gallon of fuel.
Good luck and happy trails.