Ok, maybe a stupid question but does anyone know if there is a differance between the -6 and the -4 wing kits? Vans website states that he kept the same wing but does one fit the other? A friend has a -6 wing with the Phlogiston spar that sits unassembled and a -6 empennage completed. I can aquire them veeeeerrrrrryyyyy reasonably but wanted to build a -4. Any input would be appreciated.