Question: what is the difference between a shovelhead and a knucklehead motor?
Answer: Have built many bikes and do my own work. A Shovelhead Harley engine was produced from the mid-'60s to the early '80s. ... The valve covers on these bikes was a stamped metal pan, hence the name. A Knucklehead has a rockerbox assembly that looks like a couple of knuckles and was produce from the mid-'30s to the late '40s.