W2 or R/T heads?

From this angle it looks like a water heated Holley 300-21 W-2 Street Dominator but has a few minor differences.....unless somebody recast their own similar version. It actually looks like a cross between Holley's Street and Strip Dominators! Water passage down the middle like a Street Dom. but open sides like a Strip Dom.! Mopar Performance version?
Now that I look closer, it appears to have a P number cast into it in front of the water neck. Some version of the M1 W2 I assume.