Best not to leave gas in something that sits too long. Most of the antique tractors have a cast iron bowl. Doesn’t affect it as much. It will surface rust some, but definitely nothing like carbon steel.
Damon Industries Red-Kote Gas Tank Liner I've used it on tanks, never tried it on a carb.I find a lot of those snowblower carb bowls with pinholes. I assume it’s from water sitting in the bowl for long periods. They do make a coating for the inside of gas tanks. I’ve read about guys using it on bikes and saws but I’ve never used it.