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Gear Question

Gears?

  • 4.56s

    Votes: 11 33.3%
  • 4.88s

    Votes: 22 66.7%

  • Total voters
    33

Drey

3/4 ton status
Joined
May 8, 2003
Posts
8,286
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Location
Iowa
Im trying to decide wheather to run 4.56s or 4.88s.
Truck in question will be running:
406 SBC, 700R4, NP 208, Dana 44 and 14FF
35 inch tires

The axles have 4.10s in them now, although I feel that will make the OD pretty much useless. Im leaning towards 4.88s but a few people have said 4.56s will be fine.

Ill prolly end up trying to stuff 37s or 38s under it someday

This truck will run down the road quite a bit. Although I still want to be able to the the gas to the floor and get the thrown back in the seat feeling.

The wheeling this truck will do will be primarily mud. I do intend on entering a few pickup class tractor pulls. Im sure I will run some easy to moderate trails with it someday. Only thing that hinders the trail running is I dont want to tear up the sheetmetal.


When I regear im also switching out the welded rear end for a detroit to save on my ties a bit.


So what do you guys think? 4.56s or 4.88s
 
i voted 488s...but i run 513 love um...but i also run a 205..208s have a higher low gear ratio so either will prolly be good...if you go 456 you can always pick up a 60 in the future and have a matched set insted of starting all ove...i guess it depends if your always gonna run a 44...
 
On this truck, probably wont ever throw a 60 in it
 
I vote 4.88's. If you ever go with bigger than 35" tires like you said, you will thank yourself. 4.88's and 35's wont be really that bad with the 700 anyways. Im running 4.56's and a 700 with 37's and I want 5.13's so bad. But the 4.56's do work well. For truck pulls and that pin you back in your seat feeling, youll want the lowest possible gear.
-Harrison
 
I say 4.88s. with 4.88s in overdrive your final drive ratio is about 3.42. with 35s that should make a decent ratio for highway driving. plus it will pull itself around a little better in stop and go traffic.
 
Only changing "one step" in gears, such as going from 4.10 to 4.56, is pretty small and really not that noticable.......so in other words I would consider it wasting money if you went to 4.56.

I vote for 4.88.
 
I voted for 4.88 because there was no 5.13 option. 4.56 and 35s is a really good combo, but if you ever go any bigger, you will wish you had gone 4.88 or bigger. I am about to put the 5.38s in.
 
With what you have described, I would take the engine more into consideration. Where does it make it's power, and get the best mileage? Decide if driveability and mileage are more important to you that winning the truck pulls.

Unless you built a strong bottom end in that 406 and supplied heads that flow into the higher rpm's, putting in to much gear could work against you.

An example of this would be if the motor is all done by 4500 rpm's, you might not have the wheel speed to pull that sled very far....

BTW I am anxious to see what 5.13's and a similar combo to yours feels like.:D
 
SUBFAN said:
Unless you built a strong bottom end in that 406 and supplied heads that flow into the higher rpm's, putting in to much gear could work against you.

An example of this would be if the motor is all done by 4500 rpm's, you might not have the wheel speed to pull that sled very far....


Heads and cam arent decided on my motor yet. Terry the guy building my motor said I need to decide what gears I want to run and then he will cam it accordingly. If I go 4.88s then he will move the power band up in the RPM range since the gears will help to turn the tires I wont need all my power down low as bad.
 
I ran 4.56's with 35's and a 350/700/208. great combo. chose 4.56 cause they were in the axles already. someone else said one move in gear is nothing. I agree. going from 4.10 to 4.56 is a lot of money for a small change.

4.88's:waytogo:

then when you jump the tire size again you will still have some power.
 
Cool. I just wanted you to think about how the whole combination worked together. I think the 700R4 has to deep of an overdrive, making decisions like this a bit tough.

I would be interested to know the final results as to how he built the motor and what gears you picked....
 
Ill let ya know when the truck is done...:doah:
 
I vote 5.13's but I guess that depends on how fast you want to go on the highway...

All the same setup... TC in High, tranny in OD with 35's @ 65mph... check out the RPM differences...

gearing.jpg
 
For the record, I had 4.88s put in the axles, a BTO 700R4 sits in the crate ready to be installed and the motor is almost done.

When I took my new job last year I was under the impression since I was the no longer a grunt I would have more time to go finish it. In reality I spend more time at the office taking care of added responsibiltys.
 
WOW, I didn't even realize this was like a year and a half old when I posted... :)
 
Ya your making me feel bad I dont have the damn thing done yet, haha
 

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