what are your guys opinions on oval port big block heads. closed chamber or open chamber. i know just a bout every hotrodder has heard somewhere that open chambers are better because of better breathing, but i know this guy who is highly religious with closed chamber heads and had very good success with them. of course he modified them. he was a very smart guy and ran the fastest times at the local track. He used late model (68-69) closed chamber where they are open up a bit by the factory, but not the very early ones that looked like bathtubs. then took the heads on a milling machine and cut back a bit on the exhaust(opposite side of spark plug) to unshroud the exhaust valve. then he milled .020-.025 off the deck of the head, put a nice three angle valve job and ported the ports and bowls. and lastly polished the combustion chambers. he liked closed chamber heads for a number of reasons
1. valve shrouding is really not that bad on the later(68-69) heads
2. you take have a smaller dome piston or flat top and it doesn't screw up the flame travel
3. the tighter and smaller combustion chamber gives a better and quicker fuel burn off which means you can usually run more spark advance.
4.port thses heads out and you'll have great flow.