`96 differential swap

[Shiprekd]

Hey guys,

Although new to the forum, not new to Pontiac :O} - first car was a `66 Pontiac Tempest (2 door) with OHC 6. Not a speed demon but was a classic.

Now, for the question. We have a `96 Firebird with the 3.8 and 3800 performance package. Years of heavy grocery runs by the wife has made mincemeat of the rear axles, bearings, etc..

A friend of mine has a `99 LS1 3.42 complete rear that he has offered to sell me. I have a feeling it'll bolt in knowing the 3800 package is disc brake and so is the LS1 rear. My concern is trailing arm and torque arm mounting sizes or incompatabilities.

Am I correct in any of this? or am I way off base?

Is the ratio jump going to screw up the engine/tranny settings (computer,etc..)??

The advice or help would be greatly appreciated.

[FormulaLT1]

Since your taking the whole assembly yes it will fit but just mae sure that the LS1 real isn't a traction control equiped car and the new gear ratio will throw off your speed but you can have your eprom burned from your new gear ration. Also welcome to the forum.

John

[Shiprekd]

I had a feeling the physical bolt in wouldn't be a prob. I am wondering though like you mentioned about the traction control. Now you have me thinking that the LS1 rear would be a PITA with brake line routing. They use sep. lines and different emerg cable routing; now that I try to compare a mental image.

Forgive the ignorance, I'm an old school musclecar gearhead. The newer cars I'm completely aloof with...

I'm wondering if a LT1 rear would be easier?

Any thoughts? and thanks for the warm welcome.

[FormulaLT1]

Just check on that rear end to see if it has reluctor rings at the axle ends. If it does it won't work. If it doesn't, your good to go and NP on the welcome glad to add another member to our list.

John