2020 Sierra 1500 AT4 bds lift/wheel and tire combo confusion

Avenger1 · December 10, 2020

This is my first full size truck and I’d like to lift it. I have read a lot and want to go with the BDS 4” over top Of the factory AT4 lift. What confuses me is

- I’d get fox shocks. Do I need new uca right away? No off reading. Mall crawler.
- wheel offset and backspacing confuse the life out of me. I was looking at Fuel Vapors, XD Hoss... something similar in 20” to fit 35s Nitto Ridge Grappler. But I don’t know what wheels will fit with 35s and that size lift.
- think I’m going to have them put a Borla ATAK on while it’s in. My favorite sound based on the flowmasters and such that I’ve been listening to online.

I feel like every time I find a pic of a set up w specs I got to find the wheels and they have different off sets than the set up I’ve found. So I’m lost. Help appreciated.

WACKEM_G · December 10, 2020

This is my first full size truck and I’d like to lift it. I have read a lot and want to go with the BDS 4” over top Of the factory AT4 lift. What confuses me is

- I’d get fox shocks. Do I need new uca right away? No off reading. Mall crawler.
- wheel offset and backspacing confuse the life out of me. I was looking at Fuel Vapors, XD Hoss... something similar in 20” to fit 35s Nitto Ridge Grappler. But I don’t know what wheels will fit with 35s and that size lift.
- think I’m going to have them put a Borla ATAK on while it’s in. My favorite sound based on the flowmasters and such that I’ve been listening to online.

I feel like every time I find a pic of a set up w specs I got to find the wheels and they have different off sets than the set up I’ve found. So I’m lost. Help appreciated.

Depends wht ur wanting an far u want ur wheels to stick out, I have the bds fox coilover 4in lift, I went with 20x12 -44 they stik out pretty good! Jus beware with this setup trimming will be needed.

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Avenger1 · December 10, 2020

This is a super dumb question...

Do wheels come in different off sets?

Or how do I narrow my search to wheels (20”) that have off sets that will fit 35s on the 4” BDS AT4 lift?

Supercup · December 10, 2020

5 hours ago, Avenger1 said:

This is a super dumb question...

Do wheels come in different off sets?

Or how do I narrow my search to wheels (20”) that have off sets that will fit 35s on the 4” BDS AT4 lift?

Yes they do - same sizes - often offered in a number of different offsets.

For the BDS lift - with 18" wheel you will need to have an offset of 0 to negative - to clear the new tie rod - with 20" wheels, the tie rod will go "inside" the barrel of the wheel, so some positive offsets will work

I put the 2.5" BDS lift with coilovers on my 2020 AT4 (so 4.5" over a stock truck and 2.5" over stock AT4). I have 18x9 with 18MM offset Method NV wheels, from my 2019 AT4 - had to use spacers to clear the tie rod - plan to change the wheels when I get larger tires to a -12mm offset so no spacers are required. Once you go past 0 on offset you start pushing the wheels outside the fender line - as noted by prior poster.

Find a shop in your area that installs BDS kits regularly and they will be able to help you get what you need and get the right wheels with the right offset.

You will find the BDS 2.5" or 4" with Fox coilover shocks is a great system - spend the extra $300 to get the adjustable shocks - it give you a lot more flexibility in adjusting the ride to what you like. Ride quality is improved, cv axel angle is dead level and overall offroad performance is significantly enhance over stock.

Avenger1 · December 11, 2020

I appreciate the detailed response to my newbie self. I did some more reading about off sets and then searched around on Custom Offsets for examples and what fits. It makes much more sense now though I will still check w BDS and the shop before to be certain.

I was going to go w Fox shocks but the coil over seemed like a huge price increase for what I’d be using it for.

Jgreene11 · December 13, 2020

Thanks for info. I just purchased BDS 2.5 coil over kit with fox shocks for my AT4 3.0 Duramax. Gonna run 295/70/18 Nitto Ridge Grapplers with Method 305 in 0 offset. I’ll post once installed!

Supercup · December 14, 2020

22 hours ago, Jgreene11 said:

Thanks for info. I just purchased BDS 2.5 coil over kit with fox shocks for my AT4 3.0 Duramax. Gonna run 295/70/18 Nitto Ridge Grapplers with Method 305 in 0 offset. I’ll post once installed!

Sounds like a great set up and 0 offset should be ideal! Question - I have NV 305's - in 18" I thought they only came in 18mm or -12mm - I have the 18mm, with spacers (they otherwise would not fit) - the -12mm would be the way to go with the 305.

I found with my front shocks, when delivered from the shop they were set at 8 clicks (0 full soft - 12 full stiff) - I have played with them quite a bit and for "road" use I go with 2 clicks (from full soft) and that is good ride quality, but still more composed than the Rancho. For off road I am at 6-8 clicks and for towing I am at 5 clicks.

I think the system would benefit from having an adjustable piggy back 2.5 for the rear. I talked to Fox and they gave me an option that is same shock length as the 2.0, but it is not dialed in for the truck, just an off the shelf valving. They told me the 2.0 on the back had quite a bit of valving refinement for BDS, so for now I am not switching. BDS says they plan to add a rear 2.5 option soon (but that was 8 months ago). My guess is demand would be limited, as the cost of the shocks at $1,350 for the pair, would increase cost of lift by another $1,000.

Avenger1 · December 14, 2020

Some progress but still confused.

I see people saying 20x10 -18 will fit 35x12.5 tires w the bds 4” (6 total).

one shop tried to upsell me to a 7” FTS lift. Another hasn’t gotten back to me. And BDS says I need 5.5 back space (0 off set?) to fit 35s w the lift.

but it seems there are a ton of pics on Custom Offsets of the same set up so I’m confused. Spacers? Isn’t that frowned upon?

Supercup · December 15, 2020

18 hours ago, Avenger1 said:

Some progress but still confused.

I see people saying 20x10 -18 will fit 35x12.5 tires w the bds 4” (6 total).

one shop tried to upsell me to a 7” FTS lift. Another hasn’t gotten back to me. And BDS says I need 5.5 back space (0 off set?) to fit 35s w the lift.

but it seems there are a ton of pics on Custom Offsets of the same set up so I’m confused. Spacers? Isn’t that frowned upon?

Spacers are not ideal - but in my case I already had the 18mm offset wheels - when I ordered the lift the shop thought it would fit - but it did not clear the tie rod - so spacers added to make it work.

BDS told you 0 offset, which is minimum you need to clear tie rod with 18's - anything that has negative offset (e.g. -12mm NV 305's) will give you "more" clearance on the inside and will exceed the 5.5" they told you about - they do push your tires outside your fenders a bit -

No way you get 18 x 35 x 12.5's on with 2.5" lift without major surgery to your wheel wells to create the clearance. At 2/3rd lock my 275/65/18 just rub on front edge of fender over any bump. With 0 offset or -12 offset wheel that will improve - but won't go away - so any tire larger, will require some trimming.

Here are some photos with stock duratrac's (275/65/18) to give you and idea on clearance.

Edited December 15, 2020 by Supercup

Avenger1 · December 15, 2020

Thank you very much. It would’ve been 6” total lift on 20x10 -19 w 35x12.5. Shop says it would still be too close and might require cutting and they consider that bush league. They do a lot of super high end SEMA trucks so they are a little biased but said a 7” Full Throttle lift will be best quality and clear totally. I am waiting for a quote.