I've heard that too, but also that its just a case of getting the geometry spot-on. The same thing will happen to inline-valve heads if you side load the valves, but TFS/Holleys seem to be more sensitive(or just run more often with incorrect geometry).
My Crane 2031 is .513, 214* in/.529, 220* ex and combining that with the 1.90/1.60 valves of my Edelbrocks led to clearancing my pistons quite a bit.
Every engine combination is different, but I'm going to err on the side of caution and say no, your cam is too big for that piston/valve combo. My cam would have been fine if I used GT-40 heads like I originally planned or maybe with some DSS Prolite pistons(cleared for 2.02s) instead of Speed Pros, but I got a wild hair and bought Eddies instead. The sure way to find out is to clay your pistons when you get the heads.
If its not going to work then there lies a problem. My engine is .060 over and at its limit. I don't want to open it back up to change the pistons when I really want to build a roller motor anyway. I was hopeing to get some good heads that I could use on this combo and then switch to the roller when I get around to building it
At least you have a few options that I can see, though;
1. Call a custom Ford cam grinder like Buddy Rawls or FTI and see what they can do within the limitations of your parts. Probably will be in the $300 range just for the cam.
2. Get a shelf cam with alot less duration and/or lift. You can still make alot of power even with a stock 5.0 roller cam(.444" @ valve, in/ex). It wont have a lumpy idle, though.
3. Hold off and just build another engine, or.....
4. Buy a $30 Isky piston notching tool and use it with an old stock head and gasket to notch your pistons so you can use big valves and your cam. You'll have to be careful about the depth of the notches. Its like a valve, but with a serrated face so it can cut the notches. You can only use a stock head for this if you do not use TFSs(diff valve positions).
I really don't want to change my cam out though. I'll probably end up either breaking down and getting new pistons and the heads I really want AFR 185s, or settling for 351 windsor type heads and build a whole new roller motor, mines not roller.