GR,
In case you didn't know....to be legal per NHRA the bar has to be at least 2"s above your helmet when you are buckeled in. Also it should be at least a wee bit higher than the windshield.
Set back is basically where you want it. Some are directly behind the seat-forward of the cowl, others go through the cowl as little as a 1" back from the edge.
Max, couple of hints
neck brace if you didn't have one, and a chin strap hooked to the front lower section of your helmet!
DV...the old been there, and it hurts!