Paul--thanks for the help with the aux fuel issue.  Will proceed with the wingtip option.
Steve Beckham

Your welcome Steve. I was rather pleased to find out my calculations
were not totally out to lunch :) It held five gallons!

If I had some section dwgs I could get it closer.

6-32 screws could be fine depending on the spacing per inch.
What spacing does Van use? In a case like this a whole bunch
of small screws is better than a few larger ones.

The DC3 wing is held on with a zillion 1/4 inch screws :)

Paul Lamar