I would avoid crash bars. They bend when you fall and will likely add to your injury
Engine guards are not crash bars. I see many pics of engine guards improperly installed, with pegs on them. smh.
Here is a pic of both installed on my 450. Had to fab some brackets to get the crash bars more forward, due to my forwards.
I fell with this set up, very low speed low-side left and broke my foot pretty good. Bars caught my foot up and actually caused my bike to slide quite far away from me also.
I personally will never (ever) use crash bars again, not gonna save you in a crash and have shown to actually increase rider injury. That's just facts. I do like the look though.
I think engine guards installed properly guard the engine well!
'86 CMX450 Gin-ba
'87 CMX450 Kuro
'86 CMX450 Tabo
'86 CMX450 Katai