gear debate

[Z_71_SIERRA_19]

im lifting my2005 GMC CREW CAB Z_71 truck 6 inches and want to replace my stick 3.42 gears im running 35" BF Mudders i want the truck to regain the power it had when stock i have heard to go with 4.56 but how much will that strain my tranny I AM NOT GOING TO DO ANY TYPE OF 4 WHEELING!!!!! How will 4.56 gears be on my tranny i dont want to strain it too much , i am also thinking of 4.10 gears does anyone know what i will get with these gears its going to be a daily driver and i want to be able to drive down the highway with out the engine screaming. Please if some one out there can offer some valuable info i would really appreciate it.

[Frank S]

It also depends on if you're doing any towing with the vehicle. If you are, 4.56's are going to be very necessary.

 

There was a large and heated debate on this a while back with 33" tires and need for 4.56 gears. On those tires, you don't need 4.56's unless you plan to tow or if you want to off road it. 35's are considerably larger and in many cases somewhat wider so you will experience more power loss. I'd personally go with 4.56's on 33's (though 4.10's would suffice), would definitely run them on 35's. Your transmission should not have any adverse reaction to the gears because it will actually make power easier, that is as long as you aren't taking off with your foot on the floor on a regualr basis.

 

If you're concerned about overworking the transmission have a heavy duty cooler installed for it. You'll be fine.

[Z_71_SIERRA_19]

i am not going to do any towing at all maybe just a pop up trailer from time to time how much does the cooler run?

[Shotgun]

You have asked this question before and you will probably get the same answers.You need a min of 4.56's and 4.88's wouldn't even be an over kill with 35's 33's with 4.56's would put you with an actual ratio near 4.10 ,to give you an idea.

[REDZ-71]

I'm running 4.88s with 35'' tires, it tows like a son of a gun now