When the tunnel is widened on a book chassis, the passenger side cockpit gets small. My passenger cockpit ended up 16-1/2 inches wide compared to 17-1/2 on the driver's side The frame becomes a uncomfortable pinch point. Although it may seem counterintuitive to make it smaller, filling the voids in the frame helps tremendously. I used 1" Styrofoam from the local home improvement store, with vinyl wrapped around the inside surface. The foam was made to be a tight fit so once the vinyl was wrapped, no securing was necessary. My passengers thanked me for this. We went on several long trips some greater than 10 hours with no complaints.
_________________
Chuck.
“Any suspension will work if you don’t let it.” - Colin Chapman
Visit my ongoing MGB Rustoration log:
over HEREOr my Wankel powered Locost log :
over HEREAnd don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766