Hi guys,
So right now I got a new Gov Loc Posi with 3.23 gears.
How much difference would there be in the 1/4 mile and how much harder would I feel it accelerate if i went to 3.42 gears?
I don't want to hurt my mpg to much though because its a daily driver. I have 28'' rear tires I use on the street and 26" Drag Slicks for Bracket Racing.
The Transmission is a 700R4.

Here is the work done to the engine.

-The plenum has been professionally ported.
-The runners have been professionally enlarged and honed to flow about 230cfm.
-The intake base is port matched to the bigger runners.
-I have an airfoil installed on the throttle body.
-I have the Edelbrock TES Ceramic Coated Headers and Y Pipe.
-From the Y pipe back its a 3" straight pipe with no cat and a straight through Magnaflow muffler.
-All emissions stuff removed. (live in North Dakota )
-I run a 160 thermostat in the summer and a 180 when its cooler in the spring and fall.
-I have a custom made cold air intake with K&N airfilter alot like this one.
https://www.thirdgen.org/forums/tp...ir-intake.html (air intake)
-A B&M Stage 2 Street and Strip Shift Kit.
-Lunati Voodoo 60101 Cam.

Thanks

 

Hey, Gen3,

Pardon my momentary hijack. Just curious. Have you identified the piece as a Gov-Loc? My 85 is equipped with an Auburn and 3.23's.

JamesC

 

Ya its a Gov-Loc. When I bought the car it had a open differential. So im guessing the guy who owned it last broke the original posi and just put an old open differential in it.
And last year I bought a new Gov-Loc for it but I didn't have enough money for new gears. So im wondering if its worth it to upgrade the gears to 3.42 this year.

 

IMO, you wont feel a difference.

Oh and I would sell that gov-lock. I cant stand them. Plus they are known to be weak. Id go with a powertrax lock-right if you just want a locking differential. Or a good Eaton posi unit.

 

Upgrade to a 3.42 and sell the gov lock and buy a real posi.

 

with 28 inch rear tires..alittle to big in my opinion. I did notice a fair amount seat of the pants when i went from 3.23 to 3.42. so I'm not gonna say huge difference but it is noticeable.

 

[quote=red/white04;4799624]with 28 inch rear tires..alittle to big in my opinion.quote]

Whats a little to big in your opinion ?

 

I don't like 28s, too tall... i run 26.5 seems more fitting. its just a matter of personal preferance. I think the 28s with a 3.23 would hurt your mileage more then 28's with a 3.42.

 

Thanks for the input everyone!
Anyone know how much I would gain in the 1/4 mile?

 

With 28" tires the 3.42's will help.... but how much.... You will see a little better acceleration, but I do not think you will feel it. 3.73's with the 28" tires you will see a little more yet. But what are you trying to achieve here?

 

The only reason I would go from 3.23 to 3.42 is if I was going to upgrade the hole unit. Such as a stronger ring and pinion,a 28 spline Eaton Posi with 28 spline axles, LPW support cover. Then theres the master bearing kit and axle bearing and seals. So if your going to pull the ring and pinion than this would be a good time to do it. If your going to pound on it with slicks at the raceway ¼ mile etc. than I would save my money until I could afford a 9”. I have a built/upgraded 10 bolt unit just like the one described above. My car is a daily driver and will only see the track ( with street tires)a few times to get the time down. Its really perfect for what I am using it for. Keep in mind that if you do the 10 bolt upgrade its not cheep .Including labor to install it comes to over $1,000.00. Heres a few photos of my installation.

 

Well im not putting out enough power to need a rear end that tough.
And im in college so funds are limited lol

 

I run 26'' slicks when bracket racing.
And I was hoping for 2 or 3 tenths improvement.