The Bilstein B6 4600 rear shock, part 24-021715, is a 46mm monotube damper for the rear axle of the 1990 Chevrolet C1500 454 SS. The manufacturer describes the B6 as an upgrade that keeps the factory springs and adds firmer, more precise control at OE ride height, with no lowering required. Its gas-pressure monotube body uses a 63% larger working piston for sharper damping than a conventional OE unit. Because it is sized for stock-height springs, it suits a stock-height truck, and a lowered truck needs a different unit. Bilstein says the B6 is built to OEM standards, so the price over a budget replacement buys tuned damping and a more controlled ride rather than a bolt-on look. Owners searching for a 454 SS rear monotube upgrade or a stock-height B6 4600 rear shock should confirm the application against their VIN before ordering.
Installation takes care. The manufacturer states that installation of shock absorbers requires special tools and expert knowledge, so installation of all BILSTEIN products must be performed by a qualified suspension specialist. If you do it yourself, the manufacturer also warns against clamping the shock in a vise or heating it, and says to leave the thin oil film on the piston rod in place. Keep the rear axle supported and the wheels off the ground while you work.
No. The manufacturer says the B6 is sized for stock-height springs and that the B8 is the shorter unit to use when the vehicle is lowered. Use the B6 on factory springs.
The manufacturer describes the B6 as having a gas-pressure monotube design with a larger working piston than a standard unit, which it says sharpens damping and adds control on the existing springs.
The manufacturer advises that when replacing shocks from other brands, Bilstein units should always be installed as a set. If the other rear shock is a different brand, replace both sides together. Confirm pairing details with the manufacturer.
Plan for a half-day job with a chassis hoist or jack stands, a helper, and a full set of sockets and wrenches. Owners on user forums report that a rear swap on a similar C-body truck took about two and a half hours, and that the blind nut at the top of the mount is the hardest part to reach. They also recommend holding the piston rod with a second wrench while loosening the top nut, and lowering the truck onto the suspension before final tightening of the top nut. The manufacturer also requires that all mounting fasteners be fully tightened before the suspension is loaded.
