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>> WLDR Heads data chart

Part No. Models Year Description
80009-36 WLDR 1937-1939 Front Iron head [polished]
80010-36 WLDR 1937-1939 Rear Iron head [polished]
80009-40 [set] WLDR "Special"* 1940 Special aluminium heads set for cylinders with valves closer to bore.
80009-39A [set] WLDR 1939-1941 Aluminium heads set.

* 1940 was the first year Harley-Davidson introduced "tilted valves" in the W series motor. The WLDR "Special" name that resulted from this
change is not a factory name, it was commonly used by old timers from the era and has become the name of reference. The WLDR Special is
the only motor from the WLDR series to use tilted valves. The motor was unique in other ways: it had special angled roller valve tappets and
angled valve tappet guides that were unique to that motor only.

Extra special thanks to Beachdog for providing this information gathered during more than 30 years dealing with WLDR/WR bikes.