The heads and block on the 440-3 have extra cooling passages which will be blocked using a standard head gasket. I read over at Moparts that doing this resulted in high running temps
I have read other info that says it was ok
IIRC, the motor home heads had angled 5/8 plugs, that the cfm flow was less, and had smaller valves.
To restate what I said earlier, you will probably spend more than usual to get the motor home heads to
"Some performance potential" vs starting with 452's in the first place.
