Center tube is made from 1.5" DOM tube that has 1/4" wall thickness. Soft Poly Bushings from Strong Flex in Europe. RED color - hardness of about 80 ShA* - suspension components have a hardness similar to the original metal-rubber bushes. However, strength of the polyurethane is many times greater, and the unique properties ensure long lasting comfort. *ShA - means the scale of hardness. More information about Hardness can be found at www.wikipedia.org. STEEL-IT® Paint used for maximum corrosion resistance and so you can touch them up after you get trail rash from the rocks.
MADE IN THE USA! With American DOM Tube, from American Steel Mills.
Why don't you make custom upper links?
The best replacement for the upper links is re-bushing your current stock links with the replacement Strong Flex bushings we sell or new stock upper links from the dealer. The reason why is that you can not make either the lower or the upper links longer than that are, because the upper link brackets on the axle tube already clear the Panhard/trac/lateral bar cross-member by millimeters. Longer links will collide on compression causing catastrophic damage. The upper links will never get hit by rocks and the stock units side twist quite well. The small diameter solid stock will also twist like a torsion bar. So if the bushings are shot or squeak in your stock upper links we do sell Strong Flex replacement bushings so there is no need to buy entire new links. Re-build what you already own.
FYI: The first few years that we made lower links we used Rubicon Express, Currie Johnny and Summit Machine socket joints. While these joints did have good side twist movement, the problem was that they wore VERY quickly. Rebuilding the cartridge every year is not something we are interested in.