[coldkilla]

engines are meant to be massed produced by many machines and people. whenever you have something that is very technical being handled in so many different ways during its creation, there will be slight variances and discrepencies in its specs, tolerances, clearances etc. the engineers who designed the engine take this into account and when they create the blueprints for the engine, they give the perfect number for all the specs but they also give them an upper and lower number limit that the number can fall between that is exceptable. that way all the variances during the build are taken into account and fall within the given number range, ensuring an engine that works properly. when you "blue print an engine" you are effectively hand building it to exactly meet the desired numbers the engineers deemed perfect and not just getting it within the acceptable range. engines like the new LS7 and 6.1 Hemi used in the SRT applications are built all by hand by one engine builder. this in effect allows him to "blue print the engine" at the factory. this allows for higher horse power applications because tolerances are exact and not approximate. and this is one of the reasons why cars with these motors cost so much more.