so its proven now with 190 psi of compression and jetted and a 21.5 cc head and a 100 thou of squish and for a 50/50 of c16 and pump gas will still detonate so i put another head gasket with the same set up and i got 165psi of compression with the doubled up head gasket and it ran good idled great and i was amazed so i called vitos today and got someone on the phone and was told 190 psi on a air cooled motor is way too much and that the head needs to be rechambered or buy another head from them...My question is,does the vitos bbk come with a 21cc head or someone machined it?im stumped on who has a good reputation and knows how to machine the head to run pump gas with my mods and is a decent price and has a good turn around time?