the problem is i had an engine rebuild 5 years ago and i didnt have idea on the things he done. i know they are wossner low compression. i know that i have an athena head gasket.. but dont know what thickness. had even done some headwork too... im not feeling any loss in power i just did this test since i bought a gauge for my friend. should i take all the plugs out or one at a time? i will try and test my engine on warm and post up the results.