After 20 plus years this summer I went with 4" spacers on my
B2910.
However, after tipping the tractor on its side a bit over ten years ago, my pucker factor has not reduced much. BUT intellectually I know things are improved stability wise.
My conclusion was I can worry about my tractor, or worry about my neck. Decided I would rather break the tractor than my neck. I don't expect any issues from adding the spacers...but if something does break, it won't likely be my neck. I can always buy a new tractor or repair the current one.
Spacers on the front are certainly best avoided. The stress mechanics are different, and any possible advantage is quite small...