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-   -   1984 Z28 rearend (https://www.thirdgen.org/forums/transmissions-drivetrain/512497-1984-z28-rearend.html)

AKATDOG 02-18-2009 11:28 PM

1984 Z28 rearend
 
i want to put a posi unit with 373 or 355 gears in my rearend, can someone point me in the right direction ? Thanks

DJP87Z28 02-19-2009 07:01 AM

Re: 1984 Z28 rearend
 
Find a 90-92 rear with better rear brakes , limited slip and 3:23 or 3:42 ratio. These are 10-bolts with 28 spline axle shafts.

big gear head 02-19-2009 07:04 AM

Re: 1984 Z28 rearend
 
You will need a 26 spline Eaton posi. an installation kit and a set of gears. There are no 3.55 gears for this rear end. Your other option would be a 3.42. Send me an email or PM if you want prices on the parts.

AKATDOG 02-19-2009 03:20 PM

Re: 1984 Z28 rearend
 

Originally Posted by DJP87Z28 (Post 4049767)
Find a 90-92 rear with better rear brakes , limited slip and 3:23 or 3:42 ratio. These are 10-bolts with 28 spline axle shafts.

90-92 will this bolt straight in ? and should i go with 342 or 373 gears ? thanks.

JamesC 02-19-2009 03:25 PM

Re: 1984 Z28 rearend
 

Originally Posted by AKATDOG (Post 4050336)
90-92 will this bolt straight in ? and should i go with 342 or 373 gears ? thanks.

Yes.

With a 700R4, probably 3.42's.

JamesC

AKATDOG 02-19-2009 03:45 PM

Re: 1984 Z28 rearend
 

Originally Posted by JamesC (Post 4050345)
Yes.

With a 700R4, probably 3.42's.

JamesC

ok so 90 to 92 and doesnt matter on model ? and whats the benefit of 342 over 373 gears ? Thanks for the info

JamesC 02-19-2009 04:04 PM

Re: 1984 Z28 rearend
 

Originally Posted by AKATDOG (Post 4050374)
ok so 90 to 92 and doesnt matter on model ? and whats the benefit of 342 over 373 gears ? Thanks for the info

Model doesn't matter. Decide for yourself:

https://www.thirdgen.org/forums/tran...42-3-73-a.html

JamesC

DJP87Z28 02-19-2009 04:21 PM

Re: 1984 Z28 rearend
 
You will NOT find any stock 3:73 gear ratio in any 90-92 rear axle assemblies.

JamesC 02-19-2009 05:08 PM

Re: 1984 Z28 rearend
 

Originally Posted by DJP87Z28 (Post 4050409)
You will NOT find any stock 3:73 gear ratio in any 90-92 rear axle assemblies.

True enough (IIRC, OE 3.73's ended with the L69 in 1986). Any model 90-92 will bolt in, of course. He can, however, throw whatever gears that he wishes into his current rear. The link may assist in that decision.

JamesC

AKATDOG 02-19-2009 08:06 PM

Re: 1984 Z28 rearend
 
thanks guys that user has a little diff setup to mine, i have a 350 with upgraded cam, lifters, intake, headers, exaust and a 650 carburetor with an auto 700r4 trans, anyone with a similar setup can point me to what gears im looking for, i also do a fair amout of highway driving...

BtownZ28 02-19-2009 08:29 PM

Re: 1984 Z28 rearend
 
I would think that if you have a lot highway driving then you would want the the 3.42's. You'll probably get crappy gas mileage with either set of gears but better with the 3.42. It all depends what you are looking for.

AKATDOG 02-19-2009 08:38 PM

Re: 1984 Z28 rearend
 
thanks ya it looks like the 342 are better for all around driving, ill have to start with that, thanks everyone for the info

big gear head 02-19-2009 08:41 PM

Re: 1984 Z28 rearend
 
I've got a good set of used GM 3.42s. I sell used gears for $50 if you are interested.

AKATDOG 02-19-2009 10:22 PM

Re: 1984 Z28 rearend
 
will a 28 spline posi(out of a 98 Camaro v6 auto) with 3:42 gears bolt into my rearend if i get a set of 28 spline axles from a 91 or 92 ? and how much would the axles cost cost approx. ? Thanks

big gear head 02-20-2009 07:08 AM

Re: 1984 Z28 rearend
 
Yes, all you would need to do is install 28 spline axles. You could get a set from any '90 to '92 Camaro or Firebird.

JamesC 02-20-2009 07:21 AM

Re: 1984 Z28 rearend
 

Originally Posted by big gear head (Post 4051185)
Yes, all you would need to do is install 28 spline axles. You could get a set from any '90 to '92 Camaro or Firebird.

Both Moser and Superior sell new, if that's a route you're comfortable with. IIRC, I paid $235 or so from Summit (you'll also need wheel studs). You might consider replacing bearings and seals as well.

https://www.thirdgen.org/forums/tran...ing-axles.html

JamesC

big gear head 02-20-2009 09:03 AM

Re: 1984 Z28 rearend
 
Always replace the axle bearings and seals when installing new axles.


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