Round versus square is a totally "... 'pends-on" deal. I don't have my formulas book with me, but a quick search turned up a thread in which Billy Shope has posted the formulas for the same basic topic of discussion.
Here:
http://www.hotrodders.com/forum/what...are-58279.html

All that said, Chris Alston changed the tubing on the the TCP braces from round to square. Might be worth a call to ask why. He's just up the road from us.
Man, be really careful of what you read in this regard. Some of what I just read is totally wrong!

 

I agree with Billy Shope and that is what I said earlier.

 

Round or square imo the more mounting points the better, (check out maier racing) the standard 2 point didn't appeal to me when getting the job done.

 

depends on how thick the walls are and if the bean is a soild or like a u id go for the tube ones and weld them in

 

anyone know why man hole covers are round?

 

I say get the cheaper one. They both will do fine...

 

i reckon this is the key...we're not talking about race cars are we. How much, how to fit and which one will be the most secure at the mounting point?

Any reason why you wouldn't weld them in?