rear end swap

[FROW80]

I have a 406 in my 80 malibu and was wondering what vehicle that has a posi that i can just swap. my car has the stock 2:42 gears in it now. thanks

 

[bill]

I have a 406 in my 80 malibu and was wondering what vehicle that has a posi that i can just swap. my car has the stock 2:42 gears in it now. thanks

look for the tag on the trunk lid...should see a G80 for a posi unit. All Gbodys had the option of a posi and most of the Monte Carlo SS's had them standard after the 85-86 yr model IIRC. Or you can have your rear built with a posi unit which might save some time. Good luck!

 

[pontiacgp]

problem with a 30 year old car what's on the tag may not still be in the car....

 

[FROW80]

So i can just swap the gears and axles in my housing?

 

[pontiacgp]

it depends on the power in your engine and what kind of budget you have. You might want to upgrade from a 7.5

 

[FROW80]

According to the shop it should push around 500hp or more. Its just a weekend car and wont be on a track. Also I am having a ground issue. My stereo has a lot of static and noise in it. The battery is grounded to the header bolt(as it was before) and it has a tail off of the battery thats grounded to the fender. Do I need to run a ground from the block to the frame also??? Thanks for all the help info!

 

[pontiacgp]

with an engine 500 hp+ I'd be looking for another rear end, 8.2 or an 8.5 for a ford 9". These cars have terrible grounds so I grounded the battery in the trunk to the frame and from the frame to the body in the rear and front and grounded the engine from the frame all with 4 gauge wire.

 

[FROW80]

I will try to ground it the way you did on yours. Im kinda on a budget on my gears right now after the engine build so Im looking for an inexpensive solution for now. Thanks again!!

 

[FROW80]

Well Ive tried grounding the engine to the frame and everything but I still cant get the noise out of my stereo system. All my years I have never had this problem. Any help would be great. Thanks!

 

[pontiacgp]

grounds loops are easy to cause in these cars and are a source for noise problems..

Your car's electrical system (and your stereo) use the car metal chassis as a ground (there is always current flowing through your car's metal parts). If your battery and alternator are (typically) under the hood, and you are installing an amplifier all the way back in the trunk, then current flows through that power wire you ran from the battery to the amp, and back through the metal chassis to complete the circuit.

Theoretically the car's metal has no resistance, and it should not matter where you tie grounds for amplifiers, radio, battery and alternator. They all should "look" like the same point, right? Well, the metal in your car does have resistance, and there is a potential difference from the front of the car, where the battery is to the middle of the car, where the radio is, and to the back of the car, where most amplifiers are. The potential difference of the grounds makes the whole system act as an antenna, where they pick up noise. Measure voltages at battery, amplifiers and radio. There should be very little difference between the measured voltages. If there is a difference more than 1/2 volt, then you might have noise problems.

To fix this problem, make sure that the amplifiers have a good ground first. Use at least 10 Gauge wires for the grounds (and power). If you have 2 or more amplifiers, DO NOT go from the ground terminal of one amp to the other and then from there to ground, most likely you will have noise. Ground each amplifier independently. Same thing if you have added stiffening capacitors, go to a separate ground for the cap.