How did you come up with this amazing assumption?

 

its true 4 wheeler magazine did a comparison between the 2 in lasts months mag. Insome areas the dana 60 was better and some the 9.75. I can try and find a link if it online somewhere

 

Gears that are too tall don't make your truck any faster.
Many sports cars are faster in 5th gear than 6th.

These trucks won't pull redline with 3.31, 3.55, 3.73 or 4.10 gears. But the increased RPM means you'll be closer to your torque peak with the 4.10s when running fast.

There's a member here with a built truck that's run over 150 mph with 4.10s turning 29-inch tires. He didn't lose any top end due to gears. And neither will the OP.

 

Gears do make your truck faster. If a truck with 3.73's and a truck with 4.56's raced, the truck with 3.73's would go faster. These trucks without extensive mods can not overcome their high coefficient of drag. The modular engines make peak torque by about 4000, so high rpm is useless, esp. in the trucks, by 5000 rpm the hp and tq have both dropped significantly. Many sports cars do run faster in 5th, because their is not a long enough downhill straight away to get 6th wound out. The lower gears will help with acceleration, but will not add any top end.

 

I have 4.10 in one of my trucks and in a 1/4 mile it's about 128 mph. Have done diggs 40-140 have never missed yet. fastest yet 158 and still more in it!!

 

Well thats fast, what kind of mods you have that move this rocketship?

 

i think i might just go to NASA or the airforce and barrow some Solid rocket bosters and put my tail gate down Frist F-150 to reach Mach 1

 

Oh-Oh me to, please get me some too.

 

lol if i got a few extra ill drop them at Mach 1 and maybe ull get one i think thatd be so much fun to put a soild rocket boster or a Jet engine in the bed of the truck have the intake on the roof and the tail gate down for the hot exhuast gas....That one Crazy bike that J leno has is the Jet bike it does 250 there is a 2 Sec delay from when u let off the gas to when it slows down. the engine is off a huey helicopter!!!

 

Now there's an assumption.
My blown Expy had 3.31 in it from the factory.
It pulled to a higher top speed with the 4.10s in it.

Thanks for making my point...the car pulls a higher top speed with a shorter gear ratio becuase it lacks the power to pull the taller ratio. Top speed is limited by power and/or max rpm, not the length of the straightaway.

That contradicts our shared point of the sports car being faster in 5th than 6th.

THEORETICAL top speed (based on gearing ) and ACTUAL top speed are two very different things. Just because you put a high gear into a car to give it a THEORETICAL top speed of 300mph doesn't mean it has the ability to ever achieve that speed.

 

Well if you have the power, taller gears equal better top end. I'll use Nascar, we don't use 4.56's at Daytona we use a 3.64, we don't use the 3.64 at bristol because we need the bottom end. If you drive a brick everyday, like my truck, then a lower set of gears might allow it to reach a higher speed, but in the end you lose top speed.

 

True, and you're talking about much higher power levels.
But (hypothetically) let's take it to the extreme. If you put a 2.00 rear gear into the NASCAR, it'll lose top speed because it can't pull such a tall gear. So it would have a higher top speed with the 3.64

That doesn't make sense. Theoretical top speed will be reduced, for sure. But depending on how much taller or shorter, actual top speed may be higher or lower.

Either way, as with anything else, there's several factors involved.
I think we can both agree that blanket statements like "shorter gears lose top speed" may not be accurate, because we need to know "how much shorter" the gears are. Likewise, "Taller gears give more top speed" may also be inaccurate, because we need to know "how much taller."

 

Ok, I will agree that gears can allow you to run faster if you don't have the power to push it. My truck ran 125 mph in third of the rev limiter, I have 3.55's and a 4R70w. The ratio is 1:1 in third and .71 in 4th, and with the 4.10's it would probably run about 113-117 and It would shift so early into 4th, I don't think it would pull much faster.

 

Correct me if im wrong but this is how it works with 3.55 your axle turns 3.55 times to one time of the driveshaft and with 4.10 the axle turns 4.10 times to one driveshaft turn. bigger gears increase your engines time kept in the powerband cause it keeps ur rpms higher after shifts. and will decrease the topspeed of your truck before it reaches redline.

 

Technically that is true, but:

What he's saying is our trucks fourth gear is really low, and will accelerate really slowly and maybe top out (by not going any faster) if you don't have enough power to keep things moving. With 4:10s, the RPM's would be higher in fourth gear, therefore the truck would be accelerating faster, maybe ultimately topping the truck out by reaching redline, instead of just not pulling anymore.