A fellow worker had a bunch of Brand new in the box..AC 2C Model engine spark plugs. I got one & the box it came in right in front of me. I got to find that guy...get some more. I also have 2 plugs called...STITT M80 Micro spark plug...made in Conroe, Texas&have the Box for that one also. I got a few others....got to dig them out (FIND) them & the Brand on they are! Remember...theHolt needs four....it is a 4 cyl inline engine. Do not know if I will ever be able to have goodenough eyesight to finish it. Capt,n