Help with decking or not?
Head is unknown so this can only be purely guessed at until you give us more info, as above.
Guess #1: With 9.600" deck, stock 340 heads unmilled, and Felpro 1008 head gaskets, SCR is around 9.4.
Guess #2: With the same deck and head gasket, and Edelbrock chambers at 63 cc, the SCR is 10.3.
Guess #3: If decked down to 9.588" for true zero-deck, and with Edelbrock heads and 1008 gasket, SCR is 10.6.
So what are those heads again??