For the longest time I was told 3.73's for the A4 LT1 cars because the gearing ratio for a A4 3.73 is the same as a M6 with a 4.10. I am about to buy a Auburn rear our of a LT1 SS and wanted to get rid of the 3.42's in it. I have talked to a few guys in the 9's and they have toled me that since the car will not be a daily driver and be more or a 1/4 mile car I should go with 4.10's.

Your thoughts??
I will also get a stall before the season is over and hope to be spraying it.

 

Problems that you'll see is obviously the higher cruising rpm.... like near 3k at 70 mph. You'll also be shifting into OD at about 110-115mph and keep in mind the OD part of the 4L60E is the weakest part so hard shifting there will be very tough on the tranny. You'll be better off getting 3.42s or 3.73s since they'll allow you upwards of 120-125mph traps while still being in the 1:1 gear. When you decide to approach those levels of power you won't have to go back in there and change the gears. If you want to get off the line quicker, get a higher stall TC.

Madwolf has 4.10s in his A4, so you might want to PM him to see what he has to say.

This might help too:
http://www.f-body.org/gears/

HTHs

 

if its not a daily driver i would definately go 4.10s with the a4 in fact a friend in tx has a fresh 355 shortblock 11.5 comp.,cc306,1.6rr,2.055 1.56 severe duty valves,fully ported Lt4 heads &intake,58mm holley,slp shorties,mufflex 4"system,svo 24lb inj.,3500 stall,4.10,et streets26x10s,of course tuning this car runs 11.40s @117 it weighs in at 3300lbs.the way i see it if your motor makes hp at a higher rpm the more gear you need and if you build a tq motor you need less gear.

 

4.10s are pathetic on the highway and ridiculous on street tires. No traction is a serious understatement. Might want to take those factors into consideration.

If it is truly a track only car, then they are a good choice.

 

9' with 4.11 here.

I just swapped out my T56 [.50 6th] for a built A4 [.696 OD 4th] and was AMAZED that I got 455 Kms[300 miles] on my drive home,all highway on a single tank of gas.

It is pretty crappy for street traction but since I only race at the track I don't mind,I was turning 2600-2800 [at 65-70 mph]in OD with the lockup.

I would say 4.11 without a doubt!!!