Are your pistons at .0000 deck ?
Have your heads been milled ?
If I remember correctly at .500 the valve hasn't even left the chamber off the seat.
Also flat top trw pistons are usually.090 in the hole.
This combo if the decks are stock is probably around 9.4:1 compression fyi.
No offense Your combo sounds more like mid 400 horse, I've seen many 500 HP 440s and they have a bit more than what you have planned out but you can do it, just need that cam to be right, CALL HUGHES ON MONDAY