differences in speedway motors upper control arms

[awdblazer]

what is the difference between the two? just one has a aluminum cross shaft and the other being steel?
http://www.speedwaymotors.com/IMCA-Appr ... ,2120.html
http://www.speedwaymotors.com/Chromoly- ... ,5584.html

which one would you run? thanks

 

[V8 Rumble]

It seems one is imca approved and the other isn't. The metals used could be the difference. The construction looks the same.

 

[pontiacgp]

either will work, the aluminum saves some weight and some tracks want steel. Just remember to order two right sides