Necro359

Hi. New to the forum. I found this forum while searching for tuners for my truck. I am hoping someone could give me some recommendations for tuning and shift points etc. I have a 2008 sierra crew cab shortbox with the 4.8L. 140,000km on engine, new transmission. This week I installed a cold air intake with k&n filter, headman shorty headers, and MBPR cat back exhaust. Picked up a hypertech max energy 32501 tuner yesterday. I played with the tuner a bit. Put the premium tune on, upped the rev limiter and top speed, upped 1-2 shift 500 rpm, 2-3 300 rpm, and increased shift firmness. I got the hypertech mostly to disable the AFM, but read a post here today while looking it up, that they only offer that for '09 and up. But the top speed to match tires, premium tune and shift points worked good when I went for a high speed test. I set top speed to 118mph, I only got it up to 170 km (105 mph) but it had more, just ran out of empty road. I just did a bunch of work, including fuel pump, belts, tensioners, u joints, A/C condenser and recharge, and will be putting an atoto dual din deck and subs in this weekend, so I can't afford to buy a different tuner or any other mods at this point. I need to work with what I have. I work out of town, so kind of want a long haul tune for millage (probably regular instead of premium tune) and an in town tune for performance. I think this truck has 3.08 gears. This lacks power compared to my old truck, I had a mint '05 z71 silverado extended cab short box with the aluminum H.O. L33 Engine, and I put 3.73 in it. It got written off earlier this year, I bought it back and kept the engine. New to tuning, I build muscle cars. I know gears would make a big difference, but for the amount I drive, I am sticking with what it has. My old truck was brutal on fuel. Probably will swap the cam down the road. Any recommendations are appreciated. Thanks