Hey guys I am redoing my rear end(12-bolt) and the car will be a street and strip chevelle with a t-56 that has the viper tailshaft mod. I am debating whether to go with a eaton 3-series posi or a detroit locker. I really wanna use 3.55 gears (healthy bbc). I am leaning to the eaton posi.

Now I looked up the posis and found out that moroso has a posi too, based on the eaton but made out of stronger material with more clutches(18 to 22). Though it is only offered as a 4-series carrier. Is it possible to get the moroso(eaton) as a 3-series also? Yes or no?

If not where can you get the 3-series eaton posi with the good clutches (fiber) for a good price and they ship to APO also.

Thanks for your help in advance guys,
Ben:)

Summit, 459.00 3 series eaton,carbon fiber clutches.Prices are about the same anywhere.There was a guy on ebay couple months ago selling eaton 3s for 359.00.I shyed away and went with Summit. They ship anywhere.

you're running a t-56 and you want to use 3.55 gears? I suggest something like 4.10 and up. With 3.55's and a 6speed you're going to be going into 6th at like 120 mph. That t56 is useless with 3.55 rear gears. Go with 4.10 or even 4.56

also if you want a nice posi unit, go with the detriot tru-trac, it's NICE peice

I agree go with the Eaton 3 series posi, Moroso's unit is a 4 series only.

Dave

I got my eaton 12 bolt posi from here: http://www.rearendparts.com/home.php?cat=148. $348

what's the difference between 3 and 4 series?

Thanks for all the help guys. Well 3,55s I live in Germany(overseas) and driving is a litlle faster also I wanna save some gas. The difference between a 4-series and a 3-series is the offset of the carrier I guess you can say 3-series mostly exepts 3,0??-like 3,73 gears 4-series exept 3,93 and up. But there are special gears made sometime where you can actually have the same gear ratio available for both carriers but they are more like the gears between the two.

Ok I think ill stay with the eaton then but I wonder what my rpm would be with 4,10 gears at 65mph with a t-56? (with 325/50/15)

Anther question does the moroso eaton 4-series carrier that has more clutches use the carbon fiber cluthches as well? I asume so right?

you will regret putting 355 gears behind a t56... i can assure you of that.

Detriot tru-trac, is the better all around posi

Here... check this out you can find everything you need with this calculator

http://www.f-body.org/gears/

I have nothing but good things to say about my Detroit tru-trac also. I would reccomend it over any clutch type posi unit.

Hey,

I live in Belgium and am about to redo my rear axle too.
Try Jim at http://www.jdrace.com/ he is very helpfull and ships anywhere.
I just ordered all my stuff from him

Oliver

Detroit true trac