thefrenchowl wrote:Starcain,
All genuine KR heads are cast with their casting xxxxx-xxR number cast between the fins on the valve side...
Patrick
The above is true with the exception of the -52R heads, where there were different versions of these heads....but all had the brass sparkplug insert.
Early ones had no casting number on the top of the head between the fins, but rather on the underside of the head as shown in the 2 images below.
- CC of -52R from valve side.jpg (122.09 KiB) Viewed 14238 times
- LR 52R bottom label.jpg (120.09 KiB) Viewed 14237 times
Later versions of the -52R heads had casting numbers on top as described by Patrick. In the case shown below, this -52R head had both an R casting number on the top side and the "circle E" casting number on the bottom side. As would be common with the late "circle E" castings these particular heads had the short window with the fins fully encircling the spark plug hole, as I believe did all the subsequent KR heads.
- LR late style 52R Head.jpg (70.5 KiB) Viewed 14238 times