I'm doing an LG4 V8 swap from a 1985 Firebird donor car that came with a 5 speed and 9 bolt rear end.

Here are some selective tids bits if info that have confused me from my searches.

"The tech data sheet on this site is not accurate when it comes to Firebirds because the data is about Camaros and someone added the name firebird after that fact."

True. My RPO code is GW6, which the decoder says is: AXLE REAR, 3.27 RATIO, it only listed on IROC's in the tech data.

But the lising for the firebird my axle came from is right. My 83 V6 Standard is 3:42. Just like the build sheet and tooth count said.


"RPO codes are dependant on year".

Well, now I don't know if anything is real I didn't have to specify the year for that look-up on rear axle ratio.

"All Borg Warner are posi"

That sounds too good to be true. And none of my RPO codes say posi.

"All Borg Warner are disc brake"

No, the one my garage floor has drums. Like the RPO decoder says.


Anyhow what I'm getting at is, I don't know if I should use it.

PRO's

1. people claim they are good up to 500 HP. This rear end looks bigger and better (I like big butts and I cannot lie...). But does that apply to only posi units.


2. No screwing with speedo gears since drive train matches speedo.

3. My 83 rear end makes funny noises and leaves two stripes in my underwear, eh em I mean road. Which is not normal, so I think it may break, even though everthing looks good inside.

CONS

1. Brake system is metric on Borgie and mine is standard. Change of weel cylinder needed...but I guess I should replace the E-brake system anyway.

2. 9 bolt parts are more expensive if anything goes wrong. Especially in Canada.

3. I haven't poped it open yet and won't for two weeks because I work in a far away different city right now.

4. Lower Ratio


What do you guy think abouth this. Keep or Sell? and if I try to sell, is it a hard to sell odd ball?

B W axle has 300,000 KM but taken care of. V6 axle has 230,000KM beaten into it.

 

Use the 3.42 geared axle. I think axles are the same between V6 and V8 cars, correct?

If you had a posi, you'd have the RPO code G80.

 

Yeah V6 and V8 rears are the same.

Another Q has been fomulated:

Is there an easy way (read inexpensive) to change from a mechanical speedo to an electric? I have a nice guage panel where the speedo is not mechanically driven.

My last drivetrain was auto, can some parts be swapped from the auto to the manual to accomplish this and keep the speedo accurate as well?

long shot, but worth a try.

 

Don't know, but I'll bump this to the top for you