Where to start?

[DPGDirk]

gears,
Even going from a 3:23 to a 4:56 you will only see a raise in cruise RPM by 500Rpm or so.
You want some pop off the line and towability (is that a real word? lol) with big tire, fat pig. 4:1X or bigger.


Rearend,
They are different. 2500 has bigger stronger rear end and 99% of the time has a 4:10 or 11 in it. I always get them confused. kinda weetarded like that.


NNBS intake,
Yes the throttle body is a 4 bolt and bigger vs the NBS 3 bolt.
There are a few manufactures that make a adpater plate to use your 3 bolt TB on the NNBS intake, if needed.
Typical gains are aprox 15-25HP, this comes down to many factors. Tune, headers, etc.
Its worth it! no other mod to your engine next to a cam gives as much power to $.
I have seen them sell complete with Throttle body and injectors as cheap as 150$, but usually average 200-250. If your patient. you can get one complete with Flex fuel injectors for 250.
You will want the FF injectors, as soon as you do the intake and headers. you will max out your stock injectors. The FF injectors gives you plenty of headroom on your IDC (injector duty cycle), as not to max them out.


Cam,
HELL YEA you want one! easy 35-100HP gain with a cam swap!
Obviously the more power gained = the more radical it is and more supporting mods it needs. This brings us to converters. the bigger the cam, the bigger the converter number.
Your stock is aprox 1800, a typical daily driven, small cam wants a 2600-3k.
But you Can get away with the oem convertor with the right cam.


Combine these parts with even a small cam and you drastically change the power profile of your ride. it goes from boring, even with a good aggressive tune, to a HOly shit this is Nice! This is how GM should have made these vehicles from the start!

Thank you sir! Excellent info.

How do the 1500 series rearends hold up to more power and higher stall? Maybe worthwhile to do a salvage swap to a 2500 series rear to net more strength and a 4:10 gear upgrade?
Would the 2500 series axle be a straight bolt-in?

Sounds like I really need a new intake and FF injectors! Mighty as well do all of that and a cam at the same time.
If you see a complete intake and injectors and think about it- let a brother know.

My new trans has a stall at 2500RPM currently. Sounds like I can find a mild cam that would do nicely there.

Dang-it! Yer gettin' me all excited now!

 

[ezdaar]

The first thing to break in the 1500 rear end is the shit G80 locker.
Next would be the driveshaft. They are fairly weak.

As far as the 2500 being a direct bolt in. Im fairly confident ot will.
I do know that the ujoints are larger.
So you have two choices at that point.
Do a 4L80 swap and have a 2500 driveshaft shortened to fit.
Do some digging on the link at bottom and at gmfullsize.com to find out exactly whats needed.
Its a common upgrade for big power trucks and suv's
Shit. Wait. No.
To put in a truck axle into a suv, you need to change from leaf to coil,spring perchs. Etc.
so disregaurd any fitment advice i have given so far.

Or have the axle end of your current drive shaft converted to use the bigger 2500 ujoints.

The intake. Watch ebay, they are fairly common on there.

Your converter would pair up nicely to a 212/218 cam.
Check brian tooleys website, look at his stage 1 and 2 truck cams.

Pair it all up and you will have a very responsive and torquey ride.
Just remember if you dont have one now, you need a bigger transcooler.
Look here for that.
http://www.performancetrucks.net/fo...nstall-kit-brackets-fittings-hardware-508374/

 

[DPGDirk]

The first thing to break in the 1500 rear end is the shit G80 locker.
Next would be the driveshaft. They are fairly weak.

As far as the 2500 being a direct bolt in. Im fairly confident ot will.
I do know that the ujoints are larger.
So you have two choices at that point.
Do a 4L80 swap and have a 2500 driveshaft shortened to fit.
Do some digging on the link at bottom and at gmfullsize.com to find out exactly whats needed.
Its a common upgrade for big power trucks and suv's
Shit. Wait. No.
To put in a truck axle into a suv, you need to change from leaf to coil,spring perchs. Etc.
so disregaurd any fitment advice i have given so far.

Or have the axle end of your current drive shaft converted to use the bigger 2500 ujoints.

The intake. Watch ebay, they are fairly common on there.

Your converter would pair up nicely to a 212/218 cam.
Check brian tooleys website, look at his stage 1 and 2 truck cams.

Pair it all up and you will have a very responsive and torquey ride.
Just remember if you dont have one now, you need a bigger transcooler.
Look here for that.
http://www.performancetrucks.net/fo...nstall-kit-brackets-fittings-hardware-508374/

Thanks again!~

I just had the 4L60 rebuilt though, and had a bigger trans cooler added as well.

Great info!

 

[DPGDirk]

The first thing to break in the 1500 rear end is the shit G80 locker.

Any better options? Detroit? Might as well take care of that if regearing...

 

[WhoDatBuul]

Any one gota link where I can get a blower kit for the 4.8 ?

And is it hard to just do a 4.8 to 6.0 swap?

 

[hoss08]

The 6.0 swap is relatively easy, basically drop it in and bolt it up. Obviously some tuning is required. A mildly built 6.0 will be a huge step up from the 4.8. Long tubes, small cam and a TBSS or NNBS intake manifold, bigger TB and a cold air intake on the 6.0 should make you plenty of power. It would also be the perfect time to put in a converter and Efans. Id recommend adding a transgo shift kit and upgrading the servos as well. The shift kit and servos should be done reguardless of which motor you go with.

 

[ezdaar]

TrueTrac is a very popular locker.




@WhoDatBuul
Contact Black bear for the blower.

Hoss is right tho. a 6.0 is FAR cheaper to drop in, even stock and will give you a much better base to start with.

Now thats said, Dont get it confused. a 4.8 with a KBracing, Trick performance, ON3 turbo kit can make some Awesome power!
You can make more power far easier with a turbo kit than a blower and be just as reliable as a DD.

Read here,
http://www.performancetrucks.net/forums/forced-induction-159/

 

[WhoDatBuul]

The 6.0 swap is relatively easy, basically drop it in and bolt it up. Obviously some tuning is required. A mildly built 6.0 will be a huge step up from the 4.8. Long tubes, small cam and a TBSS or NNBS intake manifold, bigger TB and a cold air intake on the 6.0 should make you plenty of power. It would also be the perfect time to put in a converter and Efans. Id recommend adding a transgo shift kit and upgrading the servos as well. The shift kit and servos should be done reguardless of which motor you go with.

Yeh im leaning more to just go N/A i dont know if ima do a cam , i heard that can mess up if ur towing. Im not 100% sure . 6.0 with a bigger TB and Long Tubes should be fun. and i just did my tranny few months ago rebuild it

 

[hoss08]

Yeh im leaning more to just go N/A i dont know if ima do a cam , i heard that can mess up if ur towing. Im not 100% sure . 6.0 with a bigger TB and Long Tubes should be fun. and i just did my tranny few months ago rebuild it

Just a basic rebuild? If that's the case you'll still want to add a shift kit and vette servo at a bare minimum. The 4l60 is pretty weak for trucks of our size and have a habit of failing even with stock power. The shift kit and vette servo will help it live longer and perform better. It'll tow better/cooler and just drive better all around. A transgo HD2 can be had for around $100 and a vette servo is under $20. If you can do regular work on your truck like brake jobs and oil changes you should be able to install the servo with no problem, they are very easy to do. There are plenty of step by step guides as well as youtube videos you can reference to. The shift kit install isnt too bad but I opted to have a local trans shop do it. Its not too invasive so the install cost is relatively cheap. I paid $130 at my local trans shop and he had it done in a couple hours. Any reputable trans shop can set up the kit to your likings. The HD2 kit has a few different options for shift firmness. I have mine set up to shift almost stock at light throttle and a nice crisp shift under full throttle.

As for the cam, there are a few good options out there. Do some searching here and over at performacetrucks, there are cams out there specifically build for trucks that make great low end power and will perform well towing. Something with low lift and a duration around 220 would be ideal for a 6.0. It will make decent gains and still be very drivable as a DD with good tuning. With the right lobe separation and tuning it could even idle as smooth as stock if that's a concern to you.

Not sure if this has been mentioned yet but if you are looking at cold air intakes your best bet is an Airaid Jr. with a good flowing drop in filter. The Jr makes just as much power as the systems that completely replace the stock airbox. Its been dyno proven and will save you a lot of money. I run an AEM dryflo filter in my Jr. and I am very happy with it. Just something to keep in mind when intake shopping. I think the intake dyno test might even be a sticky here. Either way its definitely something worth reading before you drop the cash on a CAI.

 

[shakedown067]

I did Pontiac G8 241 heads (upgraded valves and springs), longtube headers (with cats), custom exhaust, e-fans, and tune so far. I'm about the same MPG (slightly better/more consistent highway MPG) but it's a ton more fun to drive. Luckily I didn't shave the 241's down as next up is the CTS-V LSA blower and LSA cam. Now that will wake this big pig up. Should have about $1500 in the blower setup collecting both new and used parts, plus a new tune and hope to install late January/Early February. Aiming for around 425hp (stock is 285), 475tq.