Hey yall Im new here and have a few questions as I may be getting a 2006 GMC Sierra Crew Cab.

-Will it 22s fit without rubbing?
- Easiest/Affordable way to lower it a little bit (1-2")?
- Performance part thats make the biggest difference (it already has exhaust)?
air intake? throttle body spacer? headers? programmer? anything else?

Thanks for your help.

 

The rims will fit with the right tire size. I would say dont go more than a 60 series to keep from rubbing. Autozone has lowering shackles in stock for 30 bucks to drop the rear 2 inches. Look around where you live and see if anyone has tuning software for LS1's and LS based motors. I have a guy here who bought his own stuff and he tuned mine for $300. And anytime I upgrade to a bigger cam or injectors, he retunes for that at no extra charge. If you cant find one, try GOWHEATLY.com. The cost is the same except you buy another PCM for your truck. The custom tune is the better for your money. Trust me!! I had handhelds and they didnt come close in power to a custom tune.

 

Is it worth the $ to do CAI, throttle body spacer, exhaust and a tune? Would I be able to tell a difference? Any other bolt on mods that will boost power?

 

Yes. I did a friends 05 5.3L Ext. Cab with a Spectre CAI($105), just a Flowmaster muffler($60), I put a stock cam out of a 2000 T/A which has a .500 lift($50 for cam, $100 to put in), and all thats left is a tune. All together he is gonna spend about $650 and gain about 60+ HP at least. We still need to Dyno it. But when he did just the CAI he said he could tell a big difference especially in the low end. The cam helped out in the mid to top end. The tune will make the throttle more crisp and responsive throughout the powerband. Also need to add a colder thermostat and colder spark plugs. I have mine done this way and had it retuned saturday for the cam. I also had my overdrive kick in at 50 MPH instead of 30 MPH. I have all this done plus no cats and magnaflow muffler. Im gonna try and make a video tonight so you can see the before and after.

 

Was the cam new or used? Order it online? Would colder thermostat/spark plugs help a lot too?

 

The cam was used. I only installed the cam. The lifters dont even have to be taken out. I think rowdyrides.com has some guys that are selling some used LS1 cams for bout $20. Putting this cam in is pretty much the threshold before having to put stronger valve springs to prevent valve float. Anymore than a .500 lift and you need them. If you get the tune, then you need to get a cooler thermostat and colder spark plugs. The tune will advance the timing which in turn gives more power but creates more heat. A 180 temp thermostat will do just fine. If you want you can modify your own stock stat which is what I did to mine. I got it to close at 183 degrees. Any cooler than that and you go into open loop. The spark plugs, I put NGK Iridium plugs in mine and they are great.

 

The LS1 cam will go in the 4.8L V8 right ( I think thats right, its the smaller V8)? The thermostat shouldnt be too expensive right? MPG going up or down if I do all this?

 

Yes it will work in the 4.8L and the thermostat is about 30-40 bucks. Its cuz you purchase the whole housing instead of just the spring and plate. I get about 18-19 in town, and 21-22 highway. You can also port your own throttle body which will help too. The reason is with the CAI and porting the throttle body the air will flow smoother, which is a big plus for the cam. Here is a website to show you how to do it. Very easy with just a air tool and the right pads. I didnt use the metal filler so thats optional...http://www.ewurl.com/post/DIY-Portin...ttle-Body.aspx

 

Would those mods get me to/close to 350 HP?

 

yes it can