I have done it on just on a stock rebuild a few times and got a noticable gain in performance
I will add that its not just facing all the plugs the same way,it is faceing the plug the correct way for the cyl only
as in the valves move around in the head depending on the cyl
e,i,i,e,e,i,i,e looking at the exhast manny this is the valve arangement so to speak,so the plug would face the corrosponding direction
I have not done it in a while but,seems I allways faced the open part of the gap towards the cold intake charge
not real sure wich way now I thinks on it
but it what RR said
in shade tree lingo the plug gaps dont all face the front of the engine
they would face the correct direction per cyl
I will stop now...
I just wish I had wrote it down be fore I forgot