I installed a set of 1.1:1 shaft mounted non-roller rockers on my vc460 and was researching an upgrade for my 420 clone. They have the 1.2:1 and 1.3:1 roller rockers like the 1.1:1 non and or roller for the 420 clones but wasn't sure exactly what the net gain would be depending on the ratio installed. Thought this link was a good explanation of the different ratio rockers and wanted to share as well as get your feedback on the larger ratios on the 420 clones.
https://www.jegs.com/s/tech-articles/rocker-arm-ratio.html&title=Rocker+Arm+Ratio+Explained
https://www.jegs.com/s/tech-articles/rocker-arm-ratio.html&title=Rocker+Arm+Ratio+Explained