Which POSI unit ?

Which POSI unit ? - 06/14/10 11:18 PM

I am interested in having a new 489 third member built for my 65 Belvedere. I hear of Nodular casings and then different posi units. Each supplier has his own choice yet I personally are not sure what would be best for my car. Some help from my friends here would help broaden my purchase. I have been told the Sure grip,Auburn, then the Detriot TRU-trac. Cone-type then again the clutch-type gets tighter with the more power to it. Geez who can decide? All a sales pitch..

My application; 65 B body 500"stroker. 550+HP 727 with 3500 stall. Running 29" Hoosier QTP on street with Caltracs. Basically a strong street car. I do not mind an agressive unit on the street as I am not driving long distances. My choice is leaning towards 3.91 gear ratio.
Any help is well appreciated. Seems the price most guys are asking is around $1200-1400 with shipping.
Any other guys out there have anyone who builds to spec here?
Thanks .Bill.

Posted By: therocks

Re: Which POSI unit ? - 06/14/10 11:22 PM

DR Diff a member here can answer all your questions.If he sees your post he will probally answer.Rocky

Posted By: JohnRR

Re: Which POSI unit ? - 06/14/10 11:26 PM

Quote:

I am interested in having a new 489 third member built for my 65 Belvedere. I hear of Nodular casings and then different posi units. Each supplier has his own choice yet I personally are not sure what would be best for my car. Some help from my friends here would help broaden my purchase. I have been told the Sure grip,Auburn, then the Detriot TRU-trac. Cone-type then again the clutch-type gets tighter with the more power to it. Geez who can decide? All a sales pitch..

My application; 65 B body 500"stroker. 550+HP 727 with 3500 stall. Running 29" Hoosier QTP on street with Caltracs. Basically a strong street car. I do not mind an agressive unit on the street as I am not driving long distances. My choice is leaning towards 3.91 gear ratio.
Any help is well appreciated. Seems the price most guys are asking is around $1200-1400 with shipping.
Any other guys out there have anyone who builds to spec here?
Thanks .Bill.

Stay as far away as possible from an original Cone type , made by Borg Warner and ANY Auburn unit as they are also cone types and you turn them into junk in short order .

Posted By: Cab_Burge

Re: Which POSI unit ? - 06/15/10 04:56 AM

My 1st choice is a 35 spline spool and axles

2nd choice is a Dana clutch type with new clutches and steels

Also on all 8 3/4 carriers make sure and get and use a steel cap on the drivers side

Posted By: 383man

Re: Which POSI unit ? - 06/15/10 04:58 AM

I put a Detroit Locker in my 63 about 2-1/2 years ago. It has worked great for my street/strip 63 Ply. I run mid 11's at just over 3700 lbs so my guess is I make about 500 flywheel hp. The locker has worked very nice. Sometimes you feel it lock back in but nothing much as most of the time I dont know it has a Detroit Locker when driving normal. Just had it to the track last weekend as thats about the 6th time I have raced it with the Locker in it. Ron

Posted By: Stroked65Belv

Re: Which POSI unit ? - 06/18/10 07:56 PM

It appears that the Detroit Locker is the way for me to go. If any of you have this unit in your 8 3/4, I would appreciate your likes/dislikes if there are any to share with me.
Thanks for your help guys!

Posted By: therocks

Re: Which POSI unit ? - 06/18/10 08:47 PM

You might want to contact Dr Diff.Depending on how agressive you drive and if you want to race it you might think about a Dana from him.By the time you buy gears a SG unit have it set up good caps etc.The price of his Danas look better and better.Ill put one in my 65 hopefully before I trash the 391s that are in it now.Rocky

Posted By: mark42202

Re: Which POSI unit ? - 06/18/10 10:14 PM

I have a brand new Moser 8 3/4 housing with a new nodular 489 case, TruTrac w/ 4.10, 33 spline axles out of my 65 Coronet for sale. It even already has brand new disc brakes and rotors on it if you're interested. It's never had a drive shaft bolted to it and has a billet 1350 yoke too. Shoot me a pm if you're interested in any of the parts or all!

Posted By: rebel

Re: Which POSI unit ? - 06/18/10 10:47 PM

detroit locker in my 'cudas 83/4 here. sooo much better than the cone type that was in it before & more manners than the spool on the street.