12:1? change your pistons.
forget Jun cams unless you're getting them at a really good price. There are other alternatives from Skunk2 or hell, even blox "produces" good cams now because they copy their lobes from reputable engine developers like Jun.
Rocket M22X is a good cam and so are their valvetrain components.
Jun FTW
3 blind mice syndrome anybody?
Don't get me wrong, I'm not saying JUN is bad quality or doesn't perform... I would just choose to spend my money elsewhere since in order to get the most out of these cams, you need compression and if you don't want to dig into your motor - then at least have a proper fueling/engine management system so you can dynotune them