I was just wonder whats a better way to raise compression on a motor? Have the heads planed, or go with domed pistons? The reason being I was looking at from Pace parts they sell a LS6 conversion package for $3000 that has all the parts and the heads are CNC ported and the compression ratio is raised to 11.2 to 1. Later on I was planning on doing the bottom end probably a stroker or all bore. But my question is if I opt for these heads is it gonna limit my possiblities down the road for a bottom end? Also it mentions that you need to have the "intake manifold pilot bosses must be chamfered with the planed heads". What the heck does that mean, and is it something that a machine shop will have to do? Ive already done all the bolt-ons other than a cam so this looks to be my nest route. Any help would be greatly appreciated.

 

It basically means the angle that the bolts go through the intake will be changed, meaning that this machining will make it level again so that it is torqued properly etc.

Domed pistons, might be nice depending on design, but it would be much easier to do with heads/gaskets as long as you aren't looking for a major bump in compression, which I assume you aren't. Having a domed piston, would not only cost alot more (opening up the engine), but also you could argue that it shrouds the flame propogation. This is in part why hemi race cars run 2 plugs per cyl, because they share pretty much the same problem.