346236 & 3993820 Heads, Cam, Springs
I am swapping from 346236 (peanut port) to 3993820 (oval port) heads. From my research, if it is correct, both have 2.06/1.72 valves? I am swapping my cam also to a Comp Magnum Hydraulic flat tappet 11-207-3 cam, int/exh @ 050 lift 224/224, duration @ 050 lift 224/224, advertised duration 270/270, int/exh lift with factory rocker arms .510/.510. I am going to have the 820 heads rebuilt. My question is what springs do I need to get in order to handle this cam and will they be strong enough if I decide to get a cam with a little more lift, say 520/520 or 550/550?