That chassis will only cert to 8.50 now days...
thats just like mine... but with a few minor tubes
it can be a 7.50.. in the halo it needs the corner
support tubes for sure... but right now its a 8.50..
it was a 7.50 some years back just like mine was..
but they changed some rules.. if you line up the main
hoop in the right location you can move some stuff...
forget where the wheels will line up... you can fab
the brackets to move them
EDIT
Also check the wall thickness before you buy..
sand it clean and sonic it or have it done..
they increased the wall to.135 from .115 I believe