602 I use those headers on my 572-13 heads. I do trim the gasket to match the flange so they are not an obstruction to the exhaust gasses.
Are they too small for those heads???
They might be but other than custom headers to fit(big bucks)my stock engine bay and chassis there are no other choices. They seem to work pretty well on our car but at 3680 lbs. a smaller diameter header may be a good idea!
Mike