I don't know if this helps anyone out there, but in talking with M H drag tires, they said its becoming popular now to take their vintage tires and have someone put the grooves in them (for day 2 use). Thought I would pass it along. I probably will do this for my gtx when I get around to it.
take with a grain of salt. They said their vintage tires are doing well.
http://www.mandhtires.com/store.php?...mode=cat_click