ATI Performance Products offers a Vasco Main Shaft for the 4L80E/4L85E tranmission. It's 100 percent machined, heat treated and finished in ATI's Baltimore facility. It's design for center lube transmissions only, while no lube holes help eliminate premature fractures. No modifications are required for fitment, and it's made to be 75 percent stronger than 4340 and 20 percent stronger than 300M. The design was derived from ATI's extreme High HP 400 and PG shafts.