They are normally bare with red overspray on the back edge where the paint masking thingy was held when they painted the engines. The Gregory's HQ-J V8 workshop manual in the attached Ebay link has a really good colour photo of a new 1974 HJ 253 on the front. Keep an eye out at swapmeets.

http://www.ebay.com.au/itm/HQ-Holden...item2a2abf72dd