need gearing help

[poorboy411]

hey yall my blazer has 6'' lift 350/350/208 drivetrain with 35" tires and 2.73 gears. now ive been told 4.11 is too much for a daily driver but i do a lot of beach sand driving and muddy paths to get to some river fishing spots and do some light duty trailer pulling. and really want something thats going to pull me through what i need i love low end tork but dont want to over do it. thanks for any help.

 

[kyser_soze]

The biggest drawback for you is the 350 tranny, 4.11 would have the power you are looking for. If you are serious about the taller gears a 700-r4 would help you out considerably. Lower 1st gear on the tranny, for pull out power and an overdrive, .70. Otherwise you will see an increase in fuel consumption, 3.73's though, would be a nice compromise.

 

[poorboy411]

would the 700r be a bolt up conversion or are they a longer tranny. i dont mind doing some modifying ive got bout all the tools i need to do a job but im new to chevy im use to building my broncoII. i just wandering what to expect if i go that route

 

[Hossbaby50]

I would not purposefully swap in a 700R4. I have had to much bad luck with them to make that an option. To get a 700R4 that is built up right is $$$. They 700R4 is longer then you TH350 is also so you would need to figure out some driveshafts from a 700R4 truck.

If you are serious about getting deep axle gears pony up and do a 4L80E swap and get it done right the first time. That is major $$$ though.

I would say you should be just fine with 4.10 gear though. You highway RPM will be a little high but not unbearable. If you do alot of highway driving at 65+ MPH then you might consider 3.73's instead. The NP208 tcase has a 2.61 lowrange that will make up for a little less axle gear and still be fine offroad in most situations.

Alot of highway I vote 3.73's
Not alto of highway I say 4.10's

Harley

 

[az-k5]

I ran 35's with 4.10's. Nice off the line decent up the hills horrible highway RPM's. I now have 37's and push 2800+ to get above 70 MPH. I am going to 40's and will plan on using them as an overdrive.

 

[trailblazer86]

4.10 axle gears/35" tires
@50mph= 1968rpm
@60mph= 2362rpm
@70mph= 2755rpm
@80mph= 3149rpm

Sounds pretty good to me.

Good low end grunt and still not revving too high on the highway.

If you are planning to rock crawl then more gearing and a 700r sounds good too.
I am running a 700r with 4.10s . I hate the way the 700r shifts from 1st to 2nd gear. it just seems to be too big of a step.

I now have a th400 in the garage ready do go into duty.
I will be changing to 3.73's as the 31" or 32" are a little on the short side.
3.73 gears/32"tires
@50mph= 1958rpm
@70mph= 2742rpm
@80mph= 3133rpm

With the 208 transfer case. The gearing in that will be enough if I want to go slow.

 

[poorboy411]

thanks to everybody for your help the truck has decent pickup power now but any kinda load on it the motor tells it but i think the 3.73 will be my route since i do 1h45min. drive every other week to the coast drive out on the beach and fish. not much rock crawling areas round goldsboro nc just mud but thanks for the help everybody

 

[jekbrown]

5.13s.

j

 

[85mudblazin]

I second that

About 10,000 RPM, yea right in that power band