400 miles? That is not enough to get it delivered from the factory in Iowa to hardly anywhere else in the U.S. I am suspecting at least 100,400 miles.
Best sources of information, considering the mixed conflicting answers you get in this forum, would be a generic RV book, like "The RVer's Bible" which is now available as an e-book, and the "RV Repair and Maintenance Manual" from Abe Books. Equipment in RV's is generic, but what they were installing 30 years ago would have been significantly different in detail from equipment used today, or even 15-20 years ago, because of shift from manual and mechanical controls to electronic controls, particularly on LPG appliances.
Winnebago has manuals online, but not necessarily that far back. Go to winnebagoind.com, at the top of the page is an clicky for "Resources" that will take you to older manuals and brochures. I don't find even a sales brochure for the MinnieWinnie in 1985, just images of a generic Winnebago brochure. There is a brochure for the Sundancer, the model line in the Itasca brand that was equivalent to MinnieWinnie in the Winnebago brand. There are images for the 1986 MinnieWinnie brochure, but some of the product information may not be correct, as running changes were common although the model offerings did not always change from year to year.
For chassis information, you would be looking for G-series owner and repair manuals from General Motors. The G-series chassis is a different animal from the van, which was unibody. The G chassis was sold both bare and with the cab from the van. A manual for the van might fairly well cover engine offerings and cab equipment, but not chassis components and the heavier duty running gear.
Documentation for most RVs is a package of user manuals and sometimes installation manuals for most of the house equipment installed. For recent years a lot of these were published in electronic form (PDFs typically) and can often be found online, but 1985 is early in the era of electronic publishing.
