@ALB posted:While it's not a good idea for most aftermarket cams for 1.1:1 rockers, the stock cam's ramps are gentle enough and the lift low enough that a smaller engine with a stock cam, dual carbs, stock heads and 1 3/8" header will make noticeably more power and still be reliable to drive with the addition of 1.4:1 rocker arms.
What an interesting find, Al.
The stock cam torque peak is 2500 RPM, and it's all done pulling at 4000 RPM. Even with 1.4 rockers and a scavenging exhaust, those peaks only move up 500 RPM. My takeaway is that rockers may help a bit, but they play around in the margins. There's nothing that can make up for a lack of cam duration and poorly flowing heads.
Comparing those charts to a similar engine with better heads and an even slightly more aggressive cam (one with more duration) reveals that the power, as they (whoever "they" are) always say really IS in the heads. It's amazing.