I'd have to check, I don't remember a mileage limit. But it cannot be your daily transportation. You must show proof of your daily driver. They may have an age limit too.
BTW, most classic car insurance is 'agreed value', meaning it is insured up to that amount, no matter what. Normal insurance is not, you get stated 'book value' or something like that. For instance, my 77 Z28 is insured for $10k. I'm pretty sure NJM would never give me 10k if it were stolen. I pay $110 a year for insurance.
Check Hagerty's website. Also, go search the term 'insurance' at
Team Camaro (a 1st gen site) and
just read all the threads. Also Team Chevelle. It has been hashed before. You can get some company names from that too & start making phone calls.