351 heads on 1991 302

I have a set of 351 heads not sure of year havnt ran the numbers yet. Was wondering if anyone knows the gain to using these heads on the 302. Will my Mac headers im using work with these heads? Got the heads for free:D so just seeing if worth my time of using or not. 40k on motor with B cam and looking for some more pep, not looking to drag just looking for some extra juice.

About the only 351W headers worth putting on a 302 for performance gains would be the old '69 351W heads......Need to know what heads you have now and what the 351 heads are.....