I have been experimenting with a set of Vitour Galaxy radials from eBay on my '68 GTS 383 4-speed car. They are cheap for testing and so far no issues. The problem with any sticky tire is that gravel won't know if it's a drag tire or not. No sticky, no traction. Big sticky, big rock chips. This is coming from a guy that has a loooooooooong gravel road to his house. If it was me I'd run a set of M&H DOT radials. They are best of both worlds IMO.