New to TCs and researching my first purchase. I've recently read about COG and I have seen it measured in numbers such as .54 etc. does the mean the center of gravity is 4" in front of the rear axle? ...
Fact is, the advertised COG of a TC is measured with tanks empty. Unless the tanks are dead centered at that COG point (often unlikely) the addition of a substantial quantity of water will cause the COG to shift either forward or rearward depending on tank location.
As to the OP's rather substantial F-450, I doubt that he'll have much of a problem.