that crossed my mind too that the voltage limiter was pegging the gauges especially when you said the oil psi was pegged but then I thought nah that couldn't be it because there's all the physical symptoms, the white smoke, the leak at the front of the head & especially the missing and wouldn't hardly stay running. I am going to go out on a limb & say ECU/slight intake&coolant leak/bad voltage limiter as he mentioned.