My C3 can sit for months ...pump the gas 3 times and she fires right up...I did away with my stock alternator and put a HO chrome one in it when I first got it ...but in the process of doing motor updates and switching to a polished Powerdyne HOWent to a cars and coffee recently and there were 2 C3 vettes that went to leave and both had dead batteries and had to be jumped haha. One was jumped by a Mustang GT350 which made it even better.