at .510 valve lift on the exhaust on stock heads, you better check retainer to valve- guide clearance and retainer to seal clearance, as its going to be close. on the intake you should be fine though. if it doesnt clear, you will wipe out your cam lobes, plus the exh. seals. check the clearance using a soft spring, compressed air and dial indicator. you need approx. .100 in. between the seal and the retainer at max lift on the exh,so you want .510 +.100=.610 when the valve is closed.you could check the clearance without swapping the cam and/or springs, only the soft spring. if you find out you dont have enough clr , then you need to remove the heads and have them machined to shorten the guides. i believe the edelbrock heads would swallow this much lift without modification, so, if you have to machine the stock heads and planned to use edelbrocks anyway, why not do so ?