These don't fit a 2008.I would use a kyb gas adjust over the detroit brand. I like bilstein but rock auto lists a price of $172 each, um no. I put bilsteins on my avalanche when i had it and they were at that time around $80 each if i remember correctly.
Edit , i see the bilstein monotubes on amazon and rock auto for under $80, i'd use these.
Amazon.com: Bilstein (24-185967) 46mm Monotube Shock Absorber : Automotive
Buy Bilstein (24-185967) 46mm Monotube Shock Absorber: Shocks & Struts - Amazon.com ✓ FREE DELIVERY possible on eligible purchaseswww.amazon.com
rock auto and amazon both list it as a fit. Unless something is different about your truck. I realize sometimes these can be off , but 2 sites list it.These don't fit a 2008.
There's no question the bilsteins are better, but a larger busing or how they made the sleeve aren't really near the top of my concerns list.Here is a pic of where i replaced gabriel ultras with bilsteins on my avalanche. Take note of the rubber bushing size and that the bolt bushing was uniform on the bilstein, a flat piece rolled into a circle on the gabriel.
Bilstein, hands down.