I have to get batteries for the camera..............But the "V" completely stabilizes it against the bar. The only difference is I only drilled enough for the bolt heads to recess leaving more meat in the wood.
man thats some JACKED up instructions............

Yeah, I'd be a little paranoid of creating a "wedge" with the "V" - better to either add the strap as Joe says or, even better, that and cut a rectangular notch big enough for the width of the bar to get down in a little and rest on the bottom rather than on the sides of the "V"...I think if you bolted a piece of flat steel to the bottom across the length it would add strength and stop that Bowing.....
I remember those days too.....Oh yeah, cinder blocks, man that was the approved substitute for jackstands back in the day. Wouldn't even think about it now.............
Ughh, that's a bad way to go...I remember those days too.
I just heard last week of a Master sergeant in the Air Force Working on his rear brakes on one of those little hydraulic jacks and it fell off and they found him 12 hours later.
+1...I grew up paranoid about that having heard/seen so many horror stories about people losing all their fingers under transmissions, legs, arms and lives because of lousy jack/supports...
+1...
I'm getting too old to crawl around on concrete. LOL