UB Machine sells tubular uppers (and will make lowers to your specs) for circle track applications and can make them in various geometries for use with B-body spindle swaps, stock parts, etc. They come powdercoated in black, have solid bushings so no deflection, and cost around 100 dollars a pair. Thats a 300 dollar savings compared to Hotchkis/Global West and the like.
They also drop 9 pounds off the front end. I believe the hotchkis/GW units are heavier and the weight savings are nill.
Later