View Full Version : What type Posi unit to run?

05-30-2005, 03:59 PM
I am building a 9" ford and was wondering what kind of posi would best suit my needs. Such as a clutch type vs. locker (or another kind not mentioned). I want something that will hold up and not compromise drivability too much, I don't want to run a spool and I drove a GTO with a "supposed" powertrax and when making a tight turn it was popping and clicking making the whole car move around (I told the guy he had rear-end problems,later told me he had it checked out and it was fine, it was supposed to do that.) The car is going to be 99% street/highway driven but I won't be necessarily nice to it. I would like to make the occasional trip to the dragstrip. I doubt it matters but I am running a TKO-600 and a 425hp SBC

05-30-2005, 04:40 PM
If you "really" will drive it 99% on the street for fun, get a clutch type unit. An Auburn unit would be excellent. Great driveability and function. Chances are this will not be your daily so you will not wear it out.

A locker is a good, tough unit. It will ratchet going around turns which "may" be annoying to some. I run one in my vintage race car and it works perfectly. It is noisy but who cares!

05-31-2005, 01:38 PM
Get the Eaton clutch style.

05-31-2005, 04:42 PM
Eaton does not make anything 'clutch wise' for a 9". I would use a 'Tru-Trac' if you were not up to actually running a Detroit locker.


06-01-2005, 04:23 PM
oops , sorry I was thinking 10 or 12 bolt...my bad :hammer:

06-05-2005, 08:17 AM
For a 9", I'd have to say go with a Tru-Trac. I've had a few different units in my '68, and it has been the best. A friend of mine also has the Tru-trac on his '68 Firebird. He's been beating the hell out of that thing for a few years (and many miles), and it has yet to show any signs of wear. I broke the case on the stock traction lock diff, so I upgraded to an Auburn pro-series after that. It worked great when new, but it was destroyed by too many burnouts. I hear great things about the Eaton units, but they don't make them for the 9". Hope this helps,