dude, theres tech forums all these questions belong in. 

i did it on the motor that i ported and polished the heads on just 2 weeks ago the motor i did had only 75000 miles on it and no rod knock, compared to other motor with rod knock and 100000 miles not sure if that made a difference or not. I can tell some difference but not sure if its just from the porting or the egr together but i did clean the hell out of my manifolds to get all the soot out of them and hopefully they will stay clean . havent really noticed a mileage difference my pcv is still hooked up im thinking about changing that to a vacuum system instead of getting sucked into the intake though. The only thing that sucks is now my check engine light comes on after a while of driving which im pretty sure throws it into open loop so that could kill my mileage too. i just need to get the megasquirt done and installed so the factory pcm wont controll fuel and spark anymore.

you probably can use a nickel or a quarter one of the kids at school had a road sign that he let me use and i just traced and cut out the shapes.