ok,i suppose the best people to talk to are some scrutineers for the series,or someone like john taylor at pedders penrith,whose prepared cars for improved production,or get a referal from the cams office.ask what materials you need tomake the cage from,what mounting points,what sort of welding,what grade bolts,pick thier brains to death.don't use water pipe,cause the first thing they do to a new cage is check to see what it's made of.use a cross brace,it stops the main hoop collapsing.also,spring the money for a new cams manual,it's got a whole section on cages,showing you what they want.i know i've heard that rollcages have to be made by cams certified people,but if you can match the cams standards,you might be able to do it yourself. p.s. i now fro said he was with the nsw road racing club,maybe he can help.