Accel copper core spark plugs for many Chevrolet inline 6, Small Block and Big block applications that use a 14mm threaded plug. Reach is .460 and they have a tapered seat. Socket size is 5/8. Please double check your application as we are unsure of the accuracy of the ebay chart.

This listing is for 2 boxes of 566-4 so you get a total of 8 spark plugs.