Bluecollar Hotrods

iTrader: (18)

Friend's truck, ran Wednesday night.

Specs are as follows:

2013 RCSB Silverado 4.8L automatic. Airraid MIT, Speed Engineering 1.75" LTs and ORY, cat back, street tune (87 octane), FTI 3000 stall. 20" SSS replicas with 275/55-20s. Still has a 3.23 open rear, a little over 4800 lbs with driver.

Best time was 15.538 @89.41 on a 2.2XX sixty foot. Best MPH was 90.XX
100% stock the truck ran 16.9 @ 86, very disappointing.

Obviously the gears and wheels are killing it. But, a TSP 216/220 high lift cam and minimum 4.10 gears + a posi are the next mods.

nighthawk08

wow, gears and wheels are killing that thing. I had an 08 4.8, same weight. Had a rough tune and 3000 converter, nothing else and it went 14.8. was a 3.73, G80 truck with 17" wheels.

Bluecollar Hotrods

iTrader: (18)

Did you ever run it completely stock? Curious what it ran. It's odd, the older trucks 07.5-2010 seem to be faster. His cousin has a 2010 Sierra ECSB with the 4.8, it always seemed faster stock vs. stock.

nighthawk08

15.6 if i recall correctly.

I just remember the throttle was so dead, even with the converter I never had traction issues with the stock tires.

Gorske

Here is my old 2008 Sierra ECSB 4x4 full street weight tune only pass. Granted it had the 5.3 and 3.73 gears.

2008 GMC Sierra CK1500 SLE 1/4 mile trap speeds 0-60 - DragTimes.com

BlackGMC

iTrader: (31)

Does it have a 4sp or 6sp?

Bluecollar Hotrods

iTrader: (18)

It is a 4 speed auto, 4L65E - I think. Has the cam... "installed" behind the seat.

Hopefully get it in the engine and tuned this winter. Not sure how much it will help with the awful 3.23s

Bluecollar Hotrods

iTrader: (18)

Ran it last night... did the cam, posi, and 4.10 gears since last time. 14.8 @ 93, 2.2 sixty foot. Heak soaked, right off the highway. The sixty was a little slower this go around. Was hoping for a little more, but - it is what it is.