What a cool bus I bet you cannot wait to go get it. Now you will have all the room you need. You could put a hot tub in the back and still have plenty of room. Do you know what HP the engine is setup to put out? If it is DDEC you can get it turned up at any Detroit dealer. A 6v92 can put out as much as 350HP. Though you might have to get bigger injectors and some other stuff if it is a emission molested engine. If it is setup for the federal specs you should be ok just having the dealer plug in the computer and up the power. Awsome bus.
If it is setup for 320HP I would not bother getting it bumped up to 350. I have been told it can cost almost a grand to have a dealer hook up a computer to it and type in a couple of commands. At least it is a "T" drive so if you choose to do a rear end swap it will not cost an arm and a leg. From the pics on Ebay the engine looked really good. I have seen many that are covered in grease and oil. Do you know if the tranny has a retarder installed? If it is an HTB748 it does and if it is an HT740 it does not. One thing I hate about Gillig Phantoms and Flx Metros is the driver side windshield is sunken in to help lessen glare. Your bus does not have that and it looks really sharp. Good deal
The 748 has a retarder, great deal. Here is a weblink to a guy who is selling a veggy oil conversion kit for the 6V92. You sure would have the room to store the oil. He is still working on his website but as far as I know he is in business or very close. It is an automated system he is selling.