4th Gen V8 Regearing - 4.56 and 4.88

t-rex grrr 2

Junior Member
Hello,

For those that have regeared their 4th gen v8's, did you regret going with a 4.56 instead of a 4.88, and/or vice versa?

My situation is the following:

2006 V8
Currently running 295/70/17s
Considering 315/70/17s at some point
4runner is equipped with a front bumper, rear bumper swing out, and roof rack
I live at least 80 miles from the nearest dirt trail
I mainly drive trails with very little rock crawling

My main concern is picking the wrong ratio only to regret the other.

Thank you!
 
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Go 4.88! it's like 200 RPM higher at 70mph...the extra torque and driveability is far greater with 4.88s...I don't have these gears but what EVERY single person in other forums and even different platforms state is they wished they just went with the higher gears...200 RPM is nothing
 
I have 4.56s with the 315s. I also have headers and Y pipe so my torque numbers are a little better than most. Pretty happy for the most part except the trans gearing is a little lacking in thick sand. So for that type of wheeling, 4.88s would make a difference.
Hwy cruise is 2300 to 2400 at 70 mph. Cruise control very rarely kicks down over bridges and mild inclines.
But, it sounds like you should go w 4.88s considering the GVW you'll be at on the scales. Because of a LT suspension, I'm at 5640 lbs with a light steel bumper only. Rolling mass makes a difference also, so try to find a light weight tire and wheel combo to go with.
Good Luck! Let us know how you make out.
 
I'm running 4.56s with 35's (11.5 skinnies) on my '06 v8 with a rear air locker, full steel front bumper (Shrockworks), full steel skids (Shrockworks), steel tube roof rack (similar to Gobi), dual battery system and a drawer system in the back and it's great! I've wheeled it in all types of terrain (rocks, sand, mud) and it's a tank. Cruises between 70-80 comfortably on the highway, although the 35s require a little more attentiveness. I also have a stainless snorkel, DT headers, DT y-pipe and Gibson cat back exhaust system so it flows pretty freely. Tows my 21' center console boat great around town too. No clue what it weighs, but I like the way it drives.
 
I'm running 4.56s with 35's (11.5 skinnies) on my '06 v8 with a rear air locker, full steel front bumper (Shrockworks), full steel skids (Shrockworks), steel tube roof rack (similar to Gobi), dual battery system and a drawer system in the back and it's great! I've wheeled it in all types of terrain (rocks, sand, mud) and it's a tank. Cruises between 70-80 comfortably on the highway, although the 35s require a little more attentiveness. I also have a stainless snorkel, DT headers, DT y-pipe and Gibson cat back exhaust system so it flows pretty freely. Tows my 21' center console boat great around town too. No clue what it weighs, but I like the way it drives.

I bet it is a tank. Except for the secondary air system, I wish I had started w a newer model year. Your power numbers are much better than mine to start with. SS snorkel is cool idea as well.
The wider tires I run also take away from hwy performance and mileage. Skinnies are much better for all round performance, and easier to handle tight trail situations.
I'd be curious to know what your truck weighs. The truck stop CAT scales cost around $20. So I went ahead took it up there. I made sure to split the axles to know how my weight is distributed for spring and shock tuning.
 
I bet it is a tank. Except for the secondary air system, I wish I had started w a newer model year. Your power numbers are much better than mine to start with. SS snorkel is cool idea as well.
The wider tires I run also take away from hwy performance and mileage. Skinnies are much better for all round performance, and easier to handle tight trail situations.
I'd be curious to know what your truck weighs. The truck stop CAT scales cost around $20. So I went ahead took it up there. I made sure to split the axles to know how my weight is distributed for spring and shock tuning.

Yeah I've had the the Slyfox SAIS bypass installed for a while, so no issues there. I may try and get it on a scale at some point. The stainless snorkel is a piece of art! Got it from Australia through Sloop imports, but I don't think they exist anymore. Didn't care for any of the plastic snorkels out that are available for our rigs.
 
Also, do keep in mind the elevation where you play vs live! Normally aspirated engines struggle at times while playing at high elevations found in CO/UT/AZ/NM/etc. Our heavy rigs can benefit from staying in the power band while playing in the higher elevations, but if you live closer to sea level, then your RPMs are a tad higher, which of course impact your MPG. My V8 is a gas hog so probably doesn't matter to most of us what the MPG is but thought I'd throw the elevation thing out there!

From Google

On average, a normally aspirated (non-boosted) engine looses 3% of it's power for every 1,000' increase in density altitude.
 
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I'm running 4.56s with 35's (11.5 skinnies) on my '06 v8 with a rear air locker, full steel front bumper (Shrockworks), full steel skids (Shrockworks), steel tube roof rack (similar to Gobi), dual battery system and a drawer system in the back and it's great! I've wheeled it in all types of terrain (rocks, sand, mud) and it's a tank. Cruises between 70-80 comfortably on the highway, although the 35s require a little more attentiveness. I also have a stainless snorkel, DT headers, DT y-pipe and Gibson cat back exhaust system so it flows pretty freely. Tows my 21' center console boat great around town too. No clue what it weighs, but I like the way it drives.

With all of that, I need to see some pics of this beast!
 
Also, do keep in mind the elevation where you play vs live! Normally aspirated engines struggle at times while playing at high elevations found in CO/UT/AZ/NM/etc. Our heavy rigs can benefit from staying in the power band while playing in the higher elevations, but if you live closer to sea level, then your RPMs are a tad higher, which of course impact your MPG. My V8 is a gas hog so probably doesn't matter to most of us what the MPG is but thought I'd throw the elevation thing out there!

From Google

On average, a normally aspirated (non-boosted) engine looses 3% of it's power for every 1,000' increase in density altitude.

Thanks for the input!

I live at sea level and the altitude where I play ranges from 1000-5000.
 
My rig has bigger tires than mentioned in this thread, 37" mud terrains, but I regeared to 4.88s with all the steel armor. vvti V8 and long tube headers.

Altitude and grade is a valid concern, when driving through Colorado, I have to floor it up the mountain and I can hardly keep up with traffic. In flat Kansas it's fine though lol.
 

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