RE: Nasty 1/10 scale on-road cars using .21 or larger engines....come inside
FastRS4s, the dual head button for the 3.3 does work but for now it is desgned more towards a drag racer in mind. The dual plug does not aide in cooling the engine off any better than what a standard single button does. The other parts like the rod and piston would be my first mods because you can break either one of those in "STOCK" form.
As for the extra wheel idea........well that has already been done by Over_revo with his 4-tec and it worked pretty good. I am not too sure on what he did to make it all work but it worked.