Little help-lift stock '04 Z71

April 18, 2005

Hey guys, I've got an '04 Z71 ext cab GMC, I really like the extra height of the 2500HD trucks, wondering what I could do to get the extra height? I've got the 17's, my next tire upgrade is 285s, and 305s if they'll fit...what's the best bet? Pretty new to lifting trucks, but I can handle a difficult lift kit install. Want a kit I can put in and not think about again, thanks.

snoman · April 18, 2005

Hey guys, I've got an '04 Z71 ext cab GMC, I really like the extra height of the 2500HD trucks, wondering what I could do to get the extra height? I've got the 17's, my next tire upgrade is 285s, and 305s if they'll fit...what's the best bet? Pretty new to lifting trucks, but I can handle a difficult lift kit install. Want a kit I can put in and not think about again, thanks.

<{POST_SNAPBACK}>

With a IFS front end it is best not to lift it too much (maybe 2 inches tops) without a proper kit that also relocates the front differentail so that front axle shaft angle are kept reasonable especailly with oversized rubber which adds even more strain the axle shafts. Also as you go larger in tire size you add strian to driveline for overall gearing being too tall which can shorten tranny life too. You need to regear for new over sized tires because they raise effective ratio, take more pwoer to roll down the road and raising the truck also increases the drag which increases the load and power requirement too. In the 285 to 305 range you should be looking at 4.56 gears and no custom tune will restore performance loss from big tires nor negate the added drive line strain that big tires add with stock gearing. Also bear in mind when looking for the 3500HD look that the front and rear axles are a lot weaker on the 1500 than they are on the 2500HD and the 2500 axle strain wise will handle 305 a LOT easier than a 1500 will if you play hard.

happypuppy · May 16, 2007

Hey guys, I've got an '04 Z71 ext cab GMC, I really like the extra height of the 2500HD trucks, wondering what I could do to get the extra height? I've got the 17's, my next tire upgrade is 285s, and 305s if they'll fit...what's the best bet? Pretty new to lifting trucks, but I can handle a difficult lift kit install. Want a kit I can put in and not think about again, thanks.

just jak it up and do what you gots to do maine

vxaxv17 · May 16, 2007

Hey guys, I've got an '04 Z71 ext cab GMC, I really like the extra height of the 2500HD trucks, wondering what I could do to get the extra height? I've got the 17's, my next tire upgrade is 285s, and 305s if they'll fit...what's the best bet? Pretty new to lifting trucks, but I can handle a difficult lift kit install. Want a kit I can put in and not think about again, thanks.

Pretty much any quality lift you get these days is going to be put it in and not think about it again. Is the z71 2wd or 4? 4wd IFS lift kits are quite a lot of work to install as there are so many new pieces that are added to the front end. The rear is cake. I'd just go with a lift (maybe 4" - 6") and then get some nice tires to go along with it.

kman05 · May 17, 2007

Hey guys, I've got an '04 Z71 ext cab GMC, I really like the extra height of the 2500HD trucks, wondering what I could do to get the extra height? I've got the 17's, my next tire upgrade is 285s, and 305s if they'll fit...what's the best bet? Pretty new to lifting trucks, but I can handle a difficult lift kit install. Want a kit I can put in and not think about again, thanks.

Pretty much any quality lift you get these days is going to be put it in and not think about it again. Is the z71 2wd or 4? 4wd IFS lift kits are quite a lot of work to install as there are so many new pieces that are added to the front end. The rear is cake. I'd just go with a lift (maybe 4" - 6") and then get some nice tires to go along with it.

i dont think there is such a thing as a 2wd z71??

diehrd · May 17, 2007

Hey guys, I've got an '04 Z71 ext cab GMC, I really like the extra height of the 2500HD trucks, wondering what I could do to get the extra height? I've got the 17's, my next tire upgrade is 285s, and 305s if they'll fit...what's the best bet? Pretty new to lifting trucks, but I can handle a difficult lift kit install. Want a kit I can put in and not think about again, thanks.

<{POST_SNAPBACK}>

With a IFS front end it is best not to lift it too much (maybe 2 inches tops) without a proper kit that also relocates the front differentail so that front axle shaft angle are kept reasonable especailly with oversized rubber which adds even more strain the axle shafts. Also as you go larger in tire size you add strian to driveline for overall gearing being too tall which can shorten tranny life too. You need to regear for new over sized tires because they raise effective ratio, take more pwoer to roll down the road and raising the truck also increases the drag which increases the load and power requirement too. In the 285 to 305 range you should be looking at 4.56 gears and no custom tune will restore performance loss from big tires nor negate the added drive line strain that big tires add with stock gearing. Also bear in mind when looking for the 3500HD look that the front and rear axles are a lot weaker on the 1500 than they are on the 2500HD and the 2500 axle strain wise will handle 305 a LOT easier than a 1500 will if you play hard.

Running a 285 will not require a 4.56 gear , the tire is 1 inch bigger then a 265 and only 2 inches over a 245.

A custom tune will give more power , and correct speedo differences.

And a 285 is the most used tire for a first upgrade and millions and millions of truck owners have done it with no ill effects because it is such a minor change...

vxaxv17 · May 17, 2007

Hey guys, I've got an '04 Z71 ext cab GMC, I really like the extra height of the 2500HD trucks, wondering what I could do to get the extra height? I've got the 17's, my next tire upgrade is 285s, and 305s if they'll fit...what's the best bet? Pretty new to lifting trucks, but I can handle a difficult lift kit install. Want a kit I can put in and not think about again, thanks.

Pretty much any quality lift you get these days is going to be put it in and not think about it again. Is the z71 2wd or 4? 4wd IFS lift kits are quite a lot of work to install as there are so many new pieces that are added to the front end. The rear is cake. I'd just go with a lift (maybe 4" - 6") and then get some nice tires to go along with it.

i dont think there is such a thing as a 2wd z71??

Sure there are, a friend of mine has one. It came with a G80 locker but it certainly is 2wd. I always thought a 2wd z71 was just retarded because its supposed to be an offroad package and why would an offroad vehicle only have 2wd?

facn8me · May 17, 2007

Well if you want it to l "look" like a hd add a 2-3" body lift and you'll have the look. A set of 285's will fit perfect also. Now personally I've never been a fan of body lifts due to the radiator/fan positioning after wards, but many many people run them with zero problem. I'm also not a huge fan of ford keys or cranking up the tbars. Main reason is our IFS's are only built with so much travel. keys/cranking the t-bars pushes down on the lower control arm in turn limiting down travel. Picture driving along and hitting a pothole. The TIRE is supposed to drop in the hole with the shock controlling extension and compression when the tire hits the bottom or side of said pothole. with the down travel (tbars cranked ) taken away the TRUCK goes in the pot hole and the ride is harsher due to controlling more weight. or something like that. So the only correct way to lift a truck IN MY OPINION is some sort of bracket and or spindle kit to relocate the front susupension. petersons offroad recently tested 8-9 kits from mild to wild all with 35's and not one broke an axle or tranny or had been regeared(that I know of) I have 3.73's and although I would love to regear cause it's the right thing to do it's not terminal if I don't. My effective ratio is around the 3.30 is range and stock 4x4's can be ordered with 3.42's so take it for what it's worth. My tuner did give back most if not all (on premium) that I lost. I can spin the tires fairly easy which is not very bright in a 4x with 35's It's common knowledge the front and rear diffs in the 1/2 tone are weak. If ya run it hard expect to break things. I have 30k on mine so far with no complaints. (except tire time is coming up and those suckers are $$$$) If yours has 3.42's though that is going to strain it more. I recomend a tuner or tune of some sort to correct the shifting and speedo. Also a tranny cooler is never a bad idea. Expect some suspension parts to wear faster. Expect bearings a little quicker too. I have worried once about my cv's and that was a couple of weeks ago. I pulled a stuck F250 out. His front diff was on the ground. Took 3 snags to get him out. I made sure to keep the wheels straight to keep as much strain off the cv's as possible and backed off when the wheel hop started( I was on pavement). Packed up my strap and hooks and drove from tulsa to DFW area for the NASCAR race. So A lifted vehicle can work and play. I think I got around 15.8-16. miles to the gallon that whole trip. If you go 285's the weight of the wheels and tire aren't too bad but you WILL notice the 35's for sure. All and all for what I wanted I'm happy.