Guys did you ever take any measurements of the Sprint 5 seat?
I'm looking at the specs trying to find new seats for the GT6.
I think its too wide for the tub on the GT6.
Basically back to square 1 with seats, got a set of GT6 full backs, but unless I modify them they are unable to be used with my 5 point belts.
I ran them all last season, but by the last run, the stuff had come out and I was feeling the frame.
One of my UK friends has successfully installed a Caterham seat. Looking for a source in North America!