i know it's old, but a good thought exercise
BSV 5hrs, 3pax, no fuel reserve
make a fuel stop, gain a pax and reserve
regular viking has more fuel capacity, 92 gallons, 1400+ miles
@ clark1961, thank you for the file, found by searching
also found this little gem http://www.testflysundance .org/documents/aircraft/Cherokee/kr86-pilot-guide.pdf