[Barry]

Squizzy...........Bill is right........you need an engineer. if you are not going to use grid. There is a way, to stack block behind the base course, ( double stacked wall ) and up to the third or fourth row, behind the wall, to add stabilization without grid. I would suggest contacting the NCMA ( National concrete and masonry association). They have an excellent wall certification program as well. ( Most of the LA's and Engineers in this part of the country conform to their standards) At the NCMA - Segmental Retaining Walls section of the website is a substandard picture of what I'm speaking of.