Well I don't know anything about fire dept drill team events or the rules associated with them.
You haven't answered my question regarding who made that rear axle you have. Google searching for C-30 and R-90 doesn't come up with anything on the first couple of pages.
The rears that you would expect to find under a '70 C30 are either an Eaton HO72 or a Dana. Which of those is this, or if it's not one of those, what is it?
