Ok to fully clear things up

L is SP,
SP head has small squish (high compression)
SP barrel is tall (low compression)

H is R,
R head has large squish (low compression)
R barrel is short (high compression)

The best set up as long as you jet it well and keep an eye on it is a SP (L) head combined with a R (H) barrel.

So you are right. You are running the lowest compression/squish set up you can get.
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If I have to take the carbs off once more...