Help on a White 15-45 yellowstone bus

[rdukw]

After following this bus for 25 years I finally got it in my hands last weekend. I am hoping a expert may chime in and give me a little advise. I can not find any info or books on the engine. I am about to change the oil as the car has not run in over 25 years due to a stuck motor (that I have gotten freed up) and I don't know how much oil she takes or even where to pour it in.

 

Thank you in advance.