the 351w in my 65 is an 85 "police interceptor" from a crown vic cruiser. ive never thought it was anything special, other than when i buy parts, it comes up a 351 H.O. well, today, i had the front accessories off (stinkin' oil pump!) and there is an "R" cast into the front of the pass. side head. it seem i read on here that this is a pretty good head for a small block.whats the deal? valves, ports, all of the above? it has always been a strong engine, even with the 2 barrel intake, and stock exhaust manifolds (it was in a ranger then)