340valve train noise with new head gaskets

my pushrods are 7.50 long so if i bought the 7.550 length would that take care of the slack? without changing head gaskets again? i think the gaskets that were in it before were mopar performance.i never saved them just assumed felpro would make them stock .the felpro tech line said they make them thicker in case you plane the heads.wish they would say that before selling them.