[andrew]

Hey guys i got my sierra on the road with a 2in suspension lift and 215 75 15 muddies. My low low is low enough for the areas i drive im going to purchase reduction gears but im not sure which ones...i wanna run these tyres out.. ill will end up going to bigger wheels maybe 29 or 30s will i need a body lift? Someone told me if i go a 2 in body lift ill have to widen the track or it will want to roll all the time..i like the zook and the current size is ok for now my real problems with the gearing atm...i just dont want to buy gears that ill have to change if i go bigger wheels and tyres...or how big to go on said tyres..

[bumstein]

29's or 30's shouldn't need a body lift ( I don't think), or guard cutting etc. Any more than that and you will need to look at virtual lift.

4.16 TF case gears should do fine for up to 30's. Alternatively a 1ltr transfer case, especially if your running 29's.

As for track, if you increase the height of the suspension you will increase the centre of gravity and yes it is more susceptible to rolling. However the increase may or may not be significant depending on the driving you are doing, but an increased risk is there.

If you intend to put new rims on then by all means get a slightly larger offset to counteract the increased COG. I have a lift on mine, run the original rims and no problems. However this car does not do heavy offroad work with intense angles, so I'm comfortable. If I were to take the same car and decide to go rock crawling or heavier 4wding then I may decide that I'm running greater risk of rolling and decide to do something about it.

[Gwagensteve]

I'll respond to your PM tomorrow evening. Birthday dinner tonight.

[andrew]

All my stuff is steep and rocky thats why i want a low low to crawl up rocks are 30s easier to get tyres for over 29s or vice versa ?

[Kor3y101]

Depends where you live. In Brisbane I've been told it is hard to find 30x9.5x15's because most people roll around in patrols and lux's etc and have 33's and up. But the price difference is negligible between the pair and sometimes 30's are actually cheaper. Go the 30's, you won't regret it.

As for gearing. Rock crawling and steel hills, go for 6.5:1's. Your top speed in 5th low will be ~40km, but it will crawl as slow as an ant in first low! Definitely recommended!
It's what I will be going when tax time comes around again

[andrew]

Ok 30 sounds like a good round number..will they fit on my stock rims? ...what will my hi range be like with 30s and 6.5 ;1 gears....can i run out my old 215 75 15s on the 6.5:1 ?
Thanks guys

[Zook_Fan]

6.5's will be far too low on 215/75R15's and they will still be very low with 30's in high range. Stick to either the 4.16 or 4.9 ratios. 4.9 would be perfect for the 30's and it will be tolerable but rev a little high while still on your current tyres.

[andrew]

My motors pretty old anyways with 215 75s i got to hold ot pretty dlat out to stay at 100 in 5th so maybe 4.9s will be the go. Intill i get the 30s