Have 6" lift coming Thursday. Im already running 31s with body lift, shackles and keys. I know 33s won't be a problem but can I push to 35s and be safe on drive train components?

 

You can use this to calculate the new effective gear ratio. https://tiresize.com/gear-ratio-calculator/

With 35s you are down about 17% of your gear ratio. So unless you have the 3.73.1 gearing, you might be pushing things.

I'm sure others will have more specific advice.

 

I'm still running stock gu6 3.42 gears also wondering if anyone knows does the g80 code apply to both the front and the rear diff or just the rear.

 

The G80 refers to whether or not the rear axle has the locking rear end. The front axle will always be an open differential if stock.

A locking front differential can be installed in the front.

 

What do you plan to do with the truck? If you just plan to cruise the mall parking lot, it should be ok for a while. If you plan to use it offroad, you're probably going to break things. And you're definitely going to notice a loss of power. For about the same price as an IFS lift, you could swap in a solid axle and not have to worry about it.

 

My non ZR2 Blazer is a dog on 31"s with the original 3.73 gearing, I couldn't imagine how it would be on 35"s... Granted I know it's no sports car lol but the thing can hardly get out of it's own way on the road. But then again you don't install 35"s for on road performance

The only thing that it could potentially harm in the long run by running much larger tires on factory gearing is the transmission, it's going to act like you're always towing a load basically. Which causes heat build up. Heat kills transmissions.

All that aside, with 35"s on factory gearing, it is going to make actually USING those 35"s off road a little more difficult. The truck is going to have a hard time turning them. I think you'll find that 4 low is going to be a MUST any time you're on anything technical or in the mud. It's just not going to have the torque to spin them in high range when the going gets tough. And you can probably forget about towing anything more than a small aluminum boat or a single ATV on a small trailer lol

 

The power loss alone would be a deal breaker to me. It's frustrating to drive something that can barely get out of its own way, and the Blazer is no drag racer to start with.

It's a lot more than just a loss of power, though. The front suspension and steering (ball joints, idler arm, hub bearings, etc.) isn't exactly known for being durable, even with stock tires. If you put 35s on it and try to use it for anything more than show, all those parts are going to wear even faster than they normally do.

 

That is very true. A lift and wheels that offset further out doesn't help the situation either lol

 

I'm working with a ZR2 truck right now and I wouldn't even consider using the stock IFS. It's just a headache waiting to happen with 35's. 32 or 33's would be way more appropriate, preferably the 32s.