midias

I have a 355 swapped into my 84 bird and I hear some noise that MIGHT be my rear end.

https://www.thirdgen.org/forums/tran...ml#post5153836


I am hoping my engine is producing around 350hp and similar Tq so I want a decent rear.


I have spent a while searching about different stronger rears. I am not ready to go 12 bolt or 9 inch, I do not plan on getting bigger tires or going to the track I am just looking to get some parts ready just in case mine has issues.

I have noticed some people seem to have trouble finding 9 bolt parts and posi cones. I think I found some on ebay

http://www.ebay.com.au/itm/Borgwarne...item43a2382821

and also at 9bolt.com.

In general it seems that parts are harder to find, but the rear is stronger.

There is a 3.23 posi 9bolt for sale local here for 200 OBO I was thinking of picking it up and swapping out my 10 bolt.

Is it worth it to get the 9 bolt for my 355 or should I just look for a 4th gen rear end?

BlackenedBird

iTrader: (5)

A 4thy gen rear is no different than a late 3rd gen 10-bolt, except that it is wider & the limited slip in better, after 1998. 93-97 is the same axle, just wider.

4 pinion gears vs 2. Bolt in axles vs c-clips. I'd stay with the 89+ (biger b rakes) 9-bolt & just swap 98+ brakes onto it, if you need/want bigger brakes.

midias

So your saying go for the 9 bolt and forget the 98+ 4thgen?

Then later get 4thgen brakes for the 9 bolt? For now I was just planning on using my iron calipers until I could afford larger brakes.

BlackenedBird

iTrader: (5)

Pretty much my opinion of it, yeah. My plan is to put 98+ brakes on my 87 10.5" rotor/iron caliper 9-bolt. That is why I just sold the Firehawk rear axle I had, to use the $ towards 98+ brakes only for my 9-bolt.

Gotta think about your wheels too. Depending on what you have now, they may not fit. I tested mine on a 3rd gen with a 4th gen axle & it was out past the top of the fender, by over 1".

midias

OK I am going to go look at the 9 bolt. I am going to pull the back cover and check the cones. I was told it was a 3.27 anyone know the tooth count so I can double check?

BlackenedBird

iTrader: (5)

Rotate a wheel hub & watch the pinion & count. Approx. 3 1/4 wheel hub turns to 1 pinion turn = a 3.27. 3 turns would give you a 3.08. 2 3/4 turns would give you a 2.77. Etc.

InfernalVortex

iTrader: (4)

I would only go with a 9 bolt if that's what I had already.

When I did my rear end swap it was just the only thing I could finda t the time, and it had the 89-92 brakes which appealed to me quite a bit.

The posi cones available today will work but you need to have a machine shop modify the carrier or the cones themselves to make them fit.

The reason I think the 9-bolt isnt as good of an option as the 10-bolt is becuase replacement parts are too expensive. 9-bolts ARE stronger, but not by a huge margin. The difference is that if you blow up a 10-bolt there are used factory parts AND new aftermarket parts of everything inside a 10-bolt. You can put in a locker, a auburn clutch posi, a torsen posi, a huge variety of gear ratios used and new from a huge variety of vendors, and parts are common.

You blow up a 10-bolt and you can just replace what's broken with something from a junkyard. You blow up a 9-bolt and you may be out of anywhere from $200 to $700.

midias

So do you think it is worth it to go look at a $200 obo 40k mile one owner 9 bolt with a 3.27 and posi to have as a back up for my maybe dieing locking 3.73 10 bolt?

DJP87Z28

Forget the wheel turing and counting gear teeth, just check the the stamped ratio on OD of the dr gear. All Mfgs stamp the ratiio on the dr gear OD.

midias

Thanks I will look when I check it out. I figure if the cones are good I can swap it in and figure out what I want to do with my 10 bolt. For 200 why not.\


Anyone else want to add?