Big Dan!
If you look real close at this picture ...
... you will see the
removable racks & mounting system that I sell at Li'l Bear Tag-Alongs -
www.LilBear.teardrops.net/parts.html
I through-bolt the stainless steel "Quick Rails" with large fender washers on the inside and self-locking nuts, but depending on your construction, you
may be able to use lag bolts (though, I wouldn't trust them for very much weight)
My rack's towers are more suitable to the typical teardrop, IMHO, because they are more upright and less likely to interfere or make contact with the sidewalls.
Give me a holler if you would like any more info. As always, then ...
CHEERS!
Grant