Just one thing that I’m thinking with relations to the Halo and your head impacting… isn’t there a NHRA rule about helmet and Roll-bar proximity when the driver is fully strapped in?
Thus if there is X.XX amount of distance required with a helmet, and removing the helmet adds another X.XX; the rotation of your head in an accident should in theory clear the bars…
This not including all the other factors at work here.
I’m just thinking the same thing, because when I put my car back together this next winter I have a feeling I may need a full cage but I still want it a “street” car…