This is kind of gross to admit, but I never had a locked down proportion for my character. The idea was to always make him stocky with a thick frame and slightly shorter legs. If you look at some of the first drawings, those 2 details were taken to the extreme.
I've been drawing his body at 4 heads tall with the half way mark being at his belt line for quite some time. Where I had trouble was was the length of his arms and legs. I'm happy with the above chart and will be turning that into a full blow model sheet in the near future (probably). I've been itching to get Manga Studio. Maybe now would be a good time.