Head gasket selection

Im trying to figure out if I should use the .054 fel pro for the magnum head and block that is 519sd

or get the whole MR.Gasket set and use those head gaskets that are either .039 or .040 that are for an LA block

what should I do?

would a drop from 10.9 to 10.5 compression make a difference?
This would also drop my dynamic from 8.531 with the .038s to 8.2 with the .054