Thank you!Yours are not "long reach". The plugs maybe are called that, but that's to accommodate the overall length of the bronze adapter. Below are short-reach adapters vs long-reach (for thick-wall cylinder heads, like 390's, which have the yellow paint).
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Here's some background info: https://www.lightspeedaero.com/Products/Sparkplugs.htm
It’s been hard to work this out. Not sure why they make it so hard - but you are right, the ones supplied to me are short reach once in the adapter.
I guess I wanted to also make sure these were the right ones for this engine. It’s confusing - especially the lycoming document 1042 which says “
Since the same engine models can use either short or long reach spark, do not use the engine model as the only basis to identify the spark plugs to be installed on the engine per Tables 2 through 5.”
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