[stumpie2]

anytime you do any test on an engine you try to simulate a running engine. that being said, a properly running engine not run cold under normal operation, thermal expansion will make the pistons to "swell" due to heat and this is how the engine will run under normal conditions. ALL cylinders should have no more than 10 lbs. or 10% difference from highest reading to lowest reading. if you look at the cyl. heads on the engine one side is higher (normally port side), the highest cyl. is #1 and is also the odd side. as for grounding the spark plugs, yes, not doing so is an easy way to fry an ecu, switch box, icu, whatever you want to call it... this info is and industry standard across the board. not exact specs. but general rule of thumb.