I had my 06 4.8l on the dyno Wed. 4/26 . I couldn't get past the rev.and mph limiters, so the best run was in 3rd gear. Anyway it put out 239.2 hp and 246ft-lbs. torque. The afr was pretty rich at, 11.2 to 11.4 . So there is probibly 20-30more hp. there yet. I don't think that I will have any tuning done untill I get the headers and exhaust done. I have a Magnacharger for it, but I need to make sure there are no waranty probs. as the truck only has about 275 mi. on it. I can post a dyno sheet ( as soon as I figure out how to) if anyone cares. Just some info for people who are liter challenged like me.

 

Not bad for a pig rich 4.8.

 

Good #'s for a stock 4.8L.

 

You'd get better numbers if you were in 4th with a 1:1 ratio. Just get the rev and speed limiters raised and you'll see a lot better numbers, AFR aside.

Post it up!