I've been looking around on the net for ideas on building a jig to build a hard tail for the sprint and this is the best I found so far.
http://www.mammothchoppers.co.uk/news01.htm

one problem I will have is the back bone brace because the Sprint backbone is pinched and sealed shut on the end. thinking about maybe tack welding the brace to the top. any tips or opinions from people with experience with jig's before I get started would be a big help. here's a pic of the frame I'm working with and thanks in advance