[FWDLK] Short, but HOT?

[eastern sierra Adj Services <esierraadj@xxxxxxxxx>]

The FSM 'describes' the (Autolite-type) AR-42, in 14mm (shortie-length
threaded-section; I forget its technical-name) for the 325 engines
(incl Super D500 application) , BUT, a
Tech-Nek Topics bulletin (1/2 1957; vol 2 #1)
states that the AR-32 (COLDER???-plug rating?) should be used in/on the
D500 motor, when "sustained" high speed driving is involved.
"The use of P/N 1658851 (AR-42) plugs for high-speed driving will
increase the tendency
and possibility of engine failure due to pre-ignition".

TSB  #D-45 ( 3/1/57) also specifies AR-32
plugs (altho no 'length' of plug is mentioned
in either the T-NT, or the TSB).

SO, I (still) wonder about installing a 'hotter' spark plug (than the
AR-42 rating), OR, maybe, the AR-42 IS the 'hottest'  safe-rated  plug,
for our engines!

Neil