I guess I am forced to touch it! Any wall taller than the manufacturers maximum height (w/o geogrid) MUST be engineered! Weather it be by a firm or a manufacturers staff engineer it must be looked at by someone other than you! Just because your township or municipality does not require an engineer it does not mean that the wall itself doesn't need engineering! An engineer looks at soooo many things in figuring out the specifics of how to build the wall. Every wall IS NOT the same! Soil types, loads, hydrostatic pressures, backfill material, slope behind the wall, slope in front of the wall...etc all play a huge part in determining the type of wall system, backfill material, base thickness, amount of buried block, number of pulls of geogrid and the placement of each pull...etc. So, unless you are an engineer your wall NEEDS to be engineered!!!!!!!