Here, I attempted to explain what " The True " Gravity " is ... Additionally you can see how important carrying your " Unit " are to getting the correct number in the correct Units.
1) American Units weights are in pounds which is a mass; the pound has to multiplied by Gravity to make it in to a Force Component, Hence " The True Gravity Constant "
2) Metric Units Weight are in Newton's which is a Force; the Newton does not have to be multiplied by Gravity to make it a Force component..
3) It's something that is not pointed out to often, in fact almost never.
4) Notice the constant: 32.2 lbm ft / lbf sec^2 - which makes the units cancel correctly....
5) Notice the difference in how the two suffixes are used; - e.g. - between lbm : Pound Mass and lbf : Pound Force
6) 1 Slug = 14.6 kg