What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

700r4

S

skyhigh4by

1/2 ton status
Joined
Jan 20, 2014
Posts
200
Reaction score
6
Location
Nanaimo BC
I currently have a 465/208 and am heavily considering going to 700R4. I have 4:10s & 385/70/16 (37.5) tires. Low is too low to use anywhere but in the bush and 2nd is a bit too high for traffic, parking lots, ect... Not only that but it doesn't have enough on the highway either. I need another gear.

I already have a spare 241 and 208 both splined for auto. Biggest thing Im unsure about is driveshaft lengths and trans mount. Is any of what I have reusable? How much difference in length is there from 465 to 700R4?

Next I know the 700R4 is a little soft. I have a decently strong 350, tons, lockers, and pretty meaty tires. What should be done to a 700R4 to make it a little more stout and get the power to the ground?

I would do floor shift, probably keep the pedal assembly in tact so that I could switch back with ease if I ever felt like it.
 
What gear ratio are you running in your axles? That will make more of a difference than anything else.
 
It looks like he has 4.10s. That really isn't enough gear for 37.5 tires. A 700r4 that isn't built won't survive long with that gearing and tires that big.

With that axle gearing, a 700r4 isn't going to help your problems. You probably won't be able to use OD on the highway (the main reason for getting a 700), and the gearing is going to keep the 350 below it's powerband.

IMO, 4.10s and a 700 work well with 33s, maybe pushing it to 35s. If you want to keep your current tires and go to a 700, you'll likely want to gear the axles down to anywhere from a 4.88 to a 5.13. As always, opinions vary, and your choice will be dependent on what you spend most of your time doing with your rig. A doubler is also an option for gearing flexibility on a street/trail rig. If you've got the coin, Bowtie Overdrives builds some real strong 700s, might be worth checking out.
 
That's basically a 37/15/16. You want 4.88 or 5.13 with that tire, especially with a 700. Without overdrive a 4.56 could work.
 
As it is right now 1st/low is way to low to use in regular driving even if you forget the fact that its not synchronized. 2nd is too high for any kind of driving in congested areas, parking lots, traffic lights, ect... Really have to ride the clutch to make it work.

So yes I could go with lower gearing in the axles (buy new lockers too because 4:10 to 4:56 units are different are they not?) BUT thats only going to make my highway driving worse.

As it sits right now I run 3000 rpm on the freeway and the truck would happily cruise faster if I was willing to run the motor up that high and burn that much fuel. I really need another gear for the highway because unfortunately its just the way it is for me right now.

My motors setup really starts to shine around 1600rpm and falls out by 4k. How can I get my highway cruise RPM down around 1600-2000 and still have a first gear that gets it rolling?
 
Unfortunately, you need both lower gears and overdrive to fix your issue to maintain highway and low speed driveability. The 700R4 simply will not last long with your gear and tire combo.
 
From what I've read,the 700R4/NP208 and a TH400/NP208 setup is close to the same length overall as the SM465/NP208 combo,close enough that the driveshafts will work,they have enough travel in the slip yokes to make up for the slight difference..
I've not done such a swap (yet),so I cant say for sure if that's gospel or not..

I agree the gearing you now have and the 37" tires will not be an ideal setup for an overdrive tranny..
 
Well I guess my next best option is 5 spd manual? Maybe I'll just build a collection of nv3500s and get good at swapping them out :haha:
 
Any particular aversion to the NV4500? It's pretty much what you have + O/D. And not likely to burn up as quickly as a 700R4.

Everybody's happy then...right?
 
campfire said:
Any particular aversion to the NV4500? It's pretty much what you have + O/D. And not likely to burn up as quickly as a 700R4.

Everybody's happy then...right?
Click to expand...

Been looking for one for almost a year. Very hard to come by and if you ever do the price is typically $1500+ Still doesn't solve the huge gap between gears. I understand that nv3500 is a far more civilized unit. With my 465 sometimes I feel like Ive just thrown a saddle on the back of a T-rex :haha:
 
skyhigh4by said:
Been looking for one for almost a year. Very hard to come by and if you ever do the price is typically $1500+ Still doesn't solve the huge gap between gears. I understand that nv3500 is a far more civilized unit. With my 465 sometimes I feel like Ive just thrown a saddle on the back of a T-rex :haha:
Click to expand...

Yes...you will lose that "dump truck" feeling if you switch to an NV3500. They are more street-friendly than the NV4500s are. Almost like driving a very heavy car. :D
 
skyhigh4by said:
I feel like Ive just thrown a saddle on the back of a T-rex
Click to expand...
So you're saying that it feels like the awesomest thing ever? Who cares about gears...if you're riding a T-Rex you own the road, period.
 
Heck, even a raptor is gonna make you king of the road unless a T-Rex comes along.....

Reagan-Raptor-copy.jpg
 
skyhigh4by said:
As it is right now 1st/low is way to low to use in regular driving even if you forget the fact that its not synchronized. 2nd is too high for any kind of driving in congested areas, parking lots, traffic lights, ect... Really have to ride the clutch to make it work.

So yes I could go with lower gearing in the axles (buy new lockers too because 4:10 to 4:56 units are different are they not?) BUT thats only going to make my highway driving worse.

As it sits right now I run 3000 rpm on the freeway and the truck would happily cruise faster if I was willing to run the motor up that high and burn that much fuel. I really need another gear for the highway because unfortunately its just the way it is for me right now.

My motors setup really starts to shine around 1600rpm and falls out by 4k. How can I get my highway cruise RPM down around 1600-2000 and still have a first gear that gets it rolling?
Click to expand...

A 4.10 gear ratio with a 37" tire and a 4 speed manual at 3000 rpm means you're going 80 mph, maybe you should consider slowing it down some?
 
I just swapped out an SM465 and an NP208 with a Centerforce 800 dollar new clutch for a 700r4 with a Dana 300 twin stick. I like it so far but want a 4 to 1 kit for the T.C. My biggest problem is this, I don't own a chevy or a blazer and hardly come to this site. I would like to post these items for sale but I can't here with out paying to be a member. What do I do ? Sorry for the thread jack, I didn't know what to do. This is the only site that I have to pay to post.
 
4X4HIGH said:
A 4.10 gear ratio with a 37" tire and a 4 speed manual at 3000 rpm means you're going 80 mph, maybe you should consider slowing it down some?
Click to expand...
I was thinking the same thing.

I had the 465 and swapped up to a NV4500. I can definitely say its a much better shifting transmission. The throws are far more precise and tighter. NV4500s can be found used for around $500-$1k depending on the condition and location.

But still no matter what you decide, no amount of overdrive will be any of use to you with those gears and tires. Do a gear change first, then see how you like it. You'll find 2nd to be much more usable.
 
Craigslist offers free classifieds. The only reason it costs money to use this site is because it costs money to operate this site. The members here saw the value in paying to keep it going [even a few guys that don't own Chevy trucks].
 
The reason I don't want to do a gear swap is #1 cost and #2 after that Im still gonna want an overdrive. I will probably be $2500 deep by the time its all said and done with the gears and new lockers. Unless Ive missed something along the line Im pretty sure that the lockers I have for my 4.10 gears won't work with 4.56 or taller...???

The speed limit on the highway I typically drive is 120km/hr (75mph) So to keep up with traffic flow Im pretty close to 80mph. At those speeds it tracks straight as an arrow and is pretty smooth considering. My only complaint is the 3k rpm and obviously how loud the mud grapplers are howling :haha:

So yes change gears and make starting a little nicer but Im gonna loose too much on the highway.

Opinions on how an nv3500 would handle the 4.10 and 37" tires in traffic, on the highway, and in the bush?? The wheeling I do is 99% low range crawling and Im pretty gentle so not super worried about strength.
 
You must log in or register to reply here.

Latest Posts

Top Bottom