Who’s ran 5.38 gears?

[2INSANE]

I recently upgraded to 40” tires. With the 6.5 TD, 4.56 gears, np208 and 700r4 I am doing 70mph at 1900 rpm. It seems sluggish or gutless.

The bigger tires seems like there is not enough gears to get up to speed unless I over Rev it. I was thinking 5.38’s would be a good choice since these Patagonia Tires are about 1” taller than most brand 40” tires.

Has anyone ever ran 5.38’s and 40’s?

 

[Sharecropper]

Yeah I have. It seems to be what you need with the 0.70 final gearing of the 700R4 and 40" tires. I had them in my 1985 K30 civi truck when I ran my 11.00-20 NDT's back in the 1990's. The gears were taken out and the originals were put back in when I sold the truck and wanted to keep my 20" rims & tires. In fact, I might still have those gears in my spare parts bin. I'll take a look.

 

[2INSANE]

Yeah I have. It seems to be what you need with the 0.70 final gearing of the 700R4 and 40" tires. I had them in my 1985 K30 civi truck when I ran my 11.00-20 NDT's back in the 1990's. The gears were taken out and the originals were put back in when I sold the truck and wanted to keep my 20" rims & tires. In fact, I might still have those gears in my spare parts bin. I'll take a look.

Oh nice! Yes please! Yeah I think the 5.38 would be great because I do plan on going from 40’s to 42’s down the road. Plus that lower first gearwith the 700r4 helps too.

 

[CARC686]

How much lift are you running on 40s? Did you have to do some cutting?

 

[2INSANE]

How much lift are you running on 40s? Did you have to do some cutting?

She has about 5 to 5 1/2” of lift. Not really sure because I have changed things on it many times over the years.

Yes, I will need to do some front wheel well cutting as these true 40” tires do rub both sides of the wheel well when articulated.

 

[87cr250r]

Have you considered offsetting the front axle forward? I offset mine and cleared 37 inch tires without having to cut the rear of the wheel arch. I have only 1" of lift due to the offset perch.

 

[2INSANE]

Have you considered offsetting the front axle forward? I offset mine and cleared 37 inch tires without having to cut the rear of the wheel arch. I have only 1" of lift due to the offset perch.

Yep! The axle is as far forward as it will go before the steering linkage hits. Same with the rear! She is stretched at 112” wheelbase. Those 40” Patagonia tires are just HUGE! Much bigger then then most 40” tires.

 

[87cr250r]

 

[CARC686]

Have you considered offsetting the front axle forward? I offset mine and cleared 37 inch tires without having to cut the rear of the wheel arch. I have only 1" of lift due to the offset perch.

You got 37s on a 1009 with nothing but zero rates? I want to run 24 bolts on one tons, but I wrote it off because I don’t want to do a big lift.

 

[Finnegan1008]

How is that 700r4 holding up with the extra power and 40s? Have you been running it for a while or driving it hard?

still on the fence between a 700r4 and a 4L80e

 

[87cr250r]

It's a 1008. Yes, I installed only zero rates and trimmed only the front of the fender. I'm running skinny tires, 37x12.5.

 

[Valley Rock]

How is that 700r4 holding up with the extra power and 40s?

Wait, extra power ?
Where did that come from, I miss somethin ?

Cuz if you had some actual power, you wouldn't need tractor gears is all ...

Nothin wrong with tractor gears, except for the extra expense of purchasing them, and then installing them, and then having them only be good for a gutless engine with super tall tires .

MKIV BBC w/cam, headers, intake, Holley 850 FTW, negates the need for gear changes, sounds awesome too .

Flamesuit on, fire at will.

 

[Finnegan1008]

Wait, extra power ?
Where did that come from, I miss somethin ?

Cuz if you had some actual power, you wouldn't need tractor gears is all ...

Nothin wrong with tractor gears, except for the extra expense of purchasing them, and then installing them, and then having them only be good for a gutless engine with super tall tires .

MKIV BBC w/cam, headers, intake, Holley 850 FTW, negates the need for gear changes, sounds awesome too .

Flamesuit on, fire at will.

The OP has a turbo 6.5. I know it’s not a modified big block but it’s more than my stock 6.2 has!

 

[2INSANE]

How is that 700r4 holding up with the extra power and 40s? Have you been running it for a while or driving it hard?

still on the fence between a 700r4 and a 4L80e

It goes 70mph at only 1900 rpm with 4.56 and true 40” tires. I have not driven it much with the 40’s. I am saving up for 5.38 gears before having fun.

The 700r4 does great with the 37” tires and 4.56 gears. Perfect combo I think.

 

[2INSANE]

Wait, extra power ?
Where did that come from, I miss somethin ?

Cuz if you had some actual power, you wouldn't need tractor gears is all ...

Nothin wrong with tractor gears, except for the extra expense of purchasing them, and then installing them, and then having them only be good for a gutless engine with super tall tires .

MKIV BBC w/cam, headers, intake, Holley 850 FTW, negates the need for gear changes, sounds awesome too .

Flamesuit on, fire at will.

My “gutless” does quite well! It keeps up with modern day traffic. Even has the power to pass other vehicles and gets better fuel economy than any big block of its time.