Hi everyone. I'm going to do a compression test on my 409 soon. I've never seen or done one before, but I think this is how I should do it. Take all the spark plugs out and connect the tester to a particular cylinder. Turn it over a few times and note the highest compression reading and the cylinder number. Move on to the next one doing the same thing. Would this be the correct way?? I'm not sure what a good compression reading/number might be, but don't they have to be within 10 points or 10% of each other?? Thank you, Carmine.