This is the description right from UPR. 

Description:

-14 lbs. ( UPR K-member )

-Does NOT Alter Wheelbase

For use with Engine Plates

Does NOT come powder coated

Tig Welded in Billet Fixtures

4130 Seamless Chrome Moly Tubing

Lighter and Stronger than Mild Steel

Saves 39 lbs over the factory K-member

All Welding & Materials Made in the USA!

Includes steering rack bushings and bolts

Can be used with UPR Non-Adjustable, Adjustable A Arms or Factory A Arms

UPR's all new Chrome Moly K-member - will save more weight and exceed any 

strength limitations of mild steel while allowing maximum header and oil pan 

clearance. Designed for the abuse of hardcore drag race, road race, and Street 

Enthusiasts. Most importantly it will handle the everyday wear and tear of city 

& highway streets like that was it's main intent.

All of our Suspension Products are made with the Highest Quality materials and 

most expensive components. We spare no expense on our products and always 

stand behind them with our Lifetime warranty that no one else offers.