Posi rearend question

[Rochlow]

I have a 69 12 bolt that I am going to be putting new bearings and seals in. I figured why I'm in there I might as well put an Eaton posi in. I will be running a 275/60/15 tire in the rear and a 350th with a 5000 stall converter. The truck originally had a 250 6cyl and manual 3spd with 225/70/15 tire in the rear

My question is what gear should I run for highway/street use. This truck is a weekend warrior that will be driven to shows.

[hjewell2]

Originally Posted by Rochlow

I have a 69 12 bolt that I am going to be putting new bearings and seals in. I figured why I'm in there I might as well put an Eaton posi in. I will be running a 275/60/15 tire in the rear and a 350th with a 5000 stall converter. The truck originally had a 250 6cyl and manual 3spd with 225/70/15 tire in the rear

My question is what gear should I run for highway/street use. This truck is a weekend warrior that will be driven to shows.

I run a series 4 eaton with 4:11 gears th350 4200stall with 350 SBC. Tires are 275/60/15 cooper I do fine around 45-50 MPH on the road 2600-2800RPM. hittin the traps @ 6800-7000 at the track.
http://youtu.be/npwEOmpPC4s

[Rochlow]

I'm not sure I want to do 4:11 for street or highway use. I was thinking 3:73 or lower.. This truck will probably never see a drag strip.

[rollinhard]

Why such a high stall if your just running on the street and highway. Just asking.

[Rochlow]

I didn't put the motor/trans together (not really my strong point) I'm told that what was put in it.. I may be wrong. I will ask about it.

[rollinhard]

Ya I'm no tranny expert either haha but a 5000 is pretty tall I think. It would probably cook it self on long highway drives. Maybe I'm wrong but just from what I read it seems to make sense.

[Rochlow]

LOL!! OMG!! My stall number was way off!!! I just called the guys that built my trans, 1800-2200 stall. I discussed what gears I should run and it was agreed that a 3:55 would probably be best for street/highway use with a 275/60/15

[hjewell2]

Originally Posted by Rochlow

LOL!! OMG!! My stall number was way off!!! I just called the guys that built my trans, 1800-2200 stall. I discussed what gears I should run and it was agreed that a 3:55 would probably be best for street/highway use with a 275/60/15

2200 stall. I would run 3:42 or 3:55 gears. You can use this website for more info.
http://www.wallaceracing.com/Calculators.htm

[Jay W]

3.55 would rock, i have 3.73 with a TH400 and love it but if you do any amount of highway 3.55 would be great.

What gears do you have now? If im not way off I think the 250 6cyl had 3.73 or 4.11 originaly?

[Rochlow]

Wow.. So I just looked up an Eaton posi, 3:55 ring and pinion, and install kit and it came to over $800 through Summit Racing. Anyone know of anything cheaper..

However, I just found a complete kit on Ebay for $645 with free shipping

[leddzepp]

Originally Posted by Rochlow

Wow.. So I just looked up an Eaton posi, 3:55 ring and pinion, and install kit and it came to over $800 through Summit Racing. Anyone know of anything cheaper..

However, I just found a complete kit on Ebay for $645 with free shipping

Make sure they are quality gears (like Richmond), or else your rear end will howl like a coyote. $800 is about right for decent parts.

[GMC Canuck]

I run the same size tire and about the same stall with a 3.73 gear and a 700r4. In OD with the converter locked it runs 1500-1800 rpm. I'll see what it runs in third next time I'm on the highway. A 3.73 should keep your cruising RPM up above or close to your stall rpm but it's a matter of preference.

[Rochlow]

Originally Posted by leddzepp

Make sure they are quality gears (like Richmond), or else your rear end will howl like a coyote. $800 is about right for decent parts.

http://www.ebay.com/itm/GM-8-875-CHE...sories&vxp=mtr

This is the one I was thinking about. I'm going to research a bit more before I make the leap.
Thanks for all the help guys, Greatly apperciated.

[hjewell2]

Originally Posted by leddzepp

Make sure they are quality gears (like Richmond), or else your rear end will howl like a coyote. $800 is about right for decent parts.

Last I heard Richmond has been sold to Motive Gear.

[70short]

Im running TH400, 411 posi and 3000 stall hughs converter I love it. I want to install A 700R4 but in time. Not A daily driver.

[Jay W]

I bought my 3.73 eaton posi off ebay from this guy

Brydon R. Papenberg <staticz2229@gmail.com>

Great service from him and his company. I think if you look up his email up on ebay