What kind of air intake is on this 4106?
Link:
http://cgi.ebay.com/ebaymotors/GM-4106-BUS-CONVERSION-CUSTOM_W0QQitemZ130023014568QQihZ003QQcategoryZ50056QQrdZ1QQcmdZViewItem
That looks similar to the one on my 4106, mine is ducted up into the bulk head area above the engine, and I have a paper element in the center of that area. From the element, it has PVC pipe that goes to the outside corners to gather air.
JImC 4106
Wisconsin