Mark and Scott,
You might consider checking out the Slick 60's Club. They are a bunch of real knowledgeable people with a lot of experience with the preservation and restoration of 1961 to 1966 Ford F and Mercury M Series trucks. http://clubs.yahoo.com/clubs/fordpickups61to66fseries
The 240-6 and the 300-6 engines both share the same bell housing and transmission bolt patern as the small block engines, such as the 302, 351w.
Good luck with your 62 stepside project. When you get your truck ready for a photo, send me a copy and I'll post it amoung the other's on the Slick 60's garage. That goes for you too Mark!