To Swap, or not to swap, that is the question.

**HasselZ28** · 08-10-2007, 08:19 AM

Well I would like to say hello first off, I'm new to the LS1 clan. I just purchased my 2002 Z A4 about a month ago and let the Mods begin. First thing I would like to do is swap my rear end gears from the stock to either a 3.73 or a 4.10, now I have been reading through some threads and noticed that this is a touchy subject. But my situation is that I do not drive in winter, I would like to take it on trips (by trips I mean no loger than 200miles). Gas consumption is not to concerning to me, I just want the most noticable bang for my buck. Also which brands the shop that I'm thinking about taking it to reccomended Richmond and I also have heard Motive to be good as well. Basically what I want out of this car is to be a stop light sleeper, I'm probably not going to be going to the track that often. So with this I appreciate any and all help!

**Madcity T/A** · 08-10-2007, 08:22 AM

4.10's are alittle to much for an auto go with 3.73.

**67CamaroRSSS** · 08-10-2007, 08:34 AM

FYI, the "Midnight Blue" color is called Navy Blue Metallic (NBM for short) by the factory. I happen to be partial to this color myself. How many miles are there on your Z? My car is an A4 and I have 3.73 gears.

Also, besides the gears (and unless you're into N2O) your best "bang for the buck" mod will be headers (LT's if you can) and a freer flowing exhaust with a cutout. LT's, 3" ORY and a E-cutout made my car .5 sec quicker in the 1/4 mile. This was back when I had 2.73's. I was also on DR's. Haven't been back to the track with the 3.73's yet.

**Jays00ss** · 08-10-2007, 09:11 AM

my buddy I work with use to work at a differential shop and put mine in. Had it done in 2 hours. I would Highly suggest haveing them done buy someone who has done it before.
As for brand, I have motive. I would suggest Motive performance or precision or yukon they are the best and the brands my buddy recomended. I would NOT recomend richmond they are noisy and the 1 brand my buddy told me to avoid. My motives are quiet but I only have 3.90's.
When you get them done, Pay particular attention to the break in rules. You can use just regular gear oil to break in the gears. Drive for 15 minutes, stop let the rear end cool for at least an hour or 2, do this 3 times to "quench" the gears. Drive easily for 500 miles, Change the gear oil, I would suggest royal purple. Then give her hell.
I would suggest Saveing your money and get a 9" or 12 bolt (preferably a 9") for the $500 (gears, rebuild kit, oil, gasket, labor) you will spend on the gear swap, you'll be 1/4 of the way to a new and 10X better rearend. I wish I would have done this.
I am now saving for the 9".

**slims00ls1z28** · 08-10-2007, 09:45 AM

Auto 4.11's here 3600 stall as well. Best mod so far to date. I'll reserve final judgement for when I get my car back from the tune shop and install the nitrous but I did all my mods in waves and so far the Stall and gears was the best even over the Cam. I installed headers, LS6 intake at the same time and felt no where near the difference than when I did the stall only even with the stock 2.73 rear and the headers were open until I installed the rear and redid the exhaust. The next week I swapped in the Moser 9 with locker and 4.11's and it compounded the feel. Later I did the cam but it was still no where as noticable as the stall/gear combo. If I had to do it all over again I would do it 3 times again Stall+gears, Stall first of course. Biggest thing with the 4.10's is that if you go down the 1/4 on a stock engine rpm range you will be shifting into OD before the traps which is not particularly ideal on a 4L60E especially stock. Get a Cam where the max RPM's are higher than 6K and it should change that (don't know yet haven't been down the track since all this. I have motives and the only time I hear any whine is slight backing up.

**67CamaroRSSS** · 08-10-2007, 02:20 PM

D'OH! Forgot about the stall. Haven't done it yet (it's my next mod) but 1 of my buddies said he picked up .8 sec in the 1/4 with LT's and a 3600 stall TC. That put him @ 12.60's.

**9t8z28** · 08-11-2007, 07:58 AM

Originally Posted by HasselZ28

Well I would like to say hello first off, I'm new to the LS1 clan. I just purchased my 2002 Z A4 about a month ago and let the Mods begin. First thing I would like to do is swap my rear end gears from the stock to either a 3.73 or a 4.10, now I have been reading through some threads and noticed that this is a touchy subject. But my situation is that I do not drive in winter, I would like to take it on trips (by trips I mean no loger than 200miles). Gas consumption is not to concerning to me, I just want the most noticable bang for my buck. Also which brands the shop that I'm thinking about taking it to reccomended Richmond and I also have heard Motive to be good as well. Basically what I want out of this car is to be a stop light sleeper, I'm probably not going to be going to the track that often. So with this I appreciate any and all help!

Richmond is a great way to go! I gots