Mystery!!! 1936 Only 45 Cylinder Heads

[MMasa]

I'm working on a 1936 Harley RLD.
According to Palmers. 1936 45 heads did NOT have the fire dam around the spark plug, at least on the front head didn't.
I have pictured below two samples of 1936-1939 front heads. It is hard to see, but BOTH heads are drilled and tapped for a primer on the far side.
The head on the right is a three bar high compression head and as you can see, it does not have the fire dam around the plug. The head on the left is a one bar low compression head and does have the dam as well as having more fins, taller fins, etc.
Also pictured is a picture from Jerry Hatfields book "Inside Harley Davidson" It is a photo / illustration of the newly designed 45 cylinder head for 1936 that was used in advertising copy. It is also a front head.
My question is....
Was this style of head ONLY used on the front? If so, why? I'm trying to decide if I'm on a fools errand looking for a similar style rear without the dam. If you know they exist or have one, is it for sale?
Also, was this style without the dam used on ALL 1936 45's or just very early models? My VIN is relatively low, Within a few digits of 36RLD1500.
ANY insight you can offer would be greatly appreciated.
Thanks
Mark Masa

[MMasa]

Re: Mystery SOLVED!! 1936 Only 45 Cylinder Heads

When I started this thread I was wondering if a REAR early 1936 head existed without the dam around the spark plug hole. I needed one for my low VIN 1936 RLD project.
Well the mystery is solved and such a head does actually exist. Found it 5 miles from my house as a matter of fact.
Here its is;




One less thing.
Mark