<VV> Delco Rapidfire Spark Plugs

[Padgett]

Looking on the Delco web page, they show the RapidFire #4 as a substitute 
for the W8AC & R43F. SInce Rapidfires generally replace 42-43-44-45 ranges 
I wonder if anyone has ever tried them in a Corvair.

Did find that threads are measured in "reach", the distance from the gasket 
seat to the end of the threads with a 44 having a 3/8" reach, 44L 7/16", 
44F 1/2", and it looks like the original 44FF was 9/16".

The interesting thing is that a #7 RapidFire (Pontiac 400) despite only a 
3/8" reach has an extended tip which makes the distance from the gasket 
seat to the top of the electrode almost exactly the same as a W8AC.

And just for fun, the gasket measures 1/16"

Am curious, has anyone ever run a 44S or 44L  or RapidFire #7 in a Corvair 
? What happened ?

Padgett