ya. get one for yourself. I'm glad I bought one. and I have a few friends with cars we can measure as well then ;-)
make sure it's a tester that you can screw in. those push-on testers are useless unless you're arnold schwartzenegger ...
if it's a screw in one, make sure that the thread is no longer than your spark plugs. as if you screw it in too far, then you might damage the piston. but I['ve never seen that happen as they're usually very short.

Another word of advise: do NOT use tools to screw them in! solid hand tight only. They're made in such a way that you _can_ use tools, but this is only for when you cant get the thing out anymore

 

 

Hi i have a 351c i did a comp test tooday i got 150 140 140 150 125 150 155 155 is this good or bad?

 

125 is pretty low....hows that plug look compared to the others?