I have been investigating this subject for about a year.
I know of a few companies working on R&D but no solid results.
Our largest problem is valve to piston clearance. Even with HKS They say you MUST use their pistons with the cams. Probably because with stock pistons you mangle the internals.
I just put my order in for my pistons and allowed for future upgrades with a larger lift and duration. Hoping someone delivers in the near future.
