The highest gear i have run on a C2 is 39/100... its smallish indoor rug. Some people can run a bigger gear if the driving style allows them too. If you arent smooth and peg the throttle alot... you cant run a bigger gear... like Bob said youll smoke the motor... especially with todays batts. Stock is much the same but the wire diameter is alot smaller... and cant withstand the amp draw a larger gear can cause, so gear selection isnt as wide as say 19T.... in the colder months the motor may not burn up... but the comm will definitely discolor and youll burn the brushes up... unless you are running the XXX brush. Then youll just notice comm discoloration.. and the motor will smell like a small electrical fire.
The Atlas 19 supposedly needs more gear than the C2... and i have never run a Reedy 19 to comment on that. For the Monster Stock i have run as low as a 31/96 but a good ballpark starter gear for 57ish sized tires is 33/100. As mentioned earlier... the smaller/bigger the tire, the ratio needs to be adjusted to compensate.
FFIB: Did you ever get your car worked out?
- DaveW