FirstYrLS1Z

iTrader: (4)

The OEM rearend(GU5-3.23s')developed a 'growl' in Oct. 2004 on the way to SLP day in Englishlish,N.J. Being that I'm familiar with rearends,I wasn't overly concerned.I have 3 complete rearends in the garage and many gearsets hanging on the wall and many carriers sitting on the shelf.Since the 'hypertech' would accomodate a 4.56 thru its' programming,why not put the 'ultimate' gear in.Another rearend is going to be built with 2.73s' for trips,another with 3.73s' for what is considered the 'best' auto gearset and the original OEM rearend is just being rebuilt with its' original 3.23s.It had a deteriorated right side carrier bearing.
Now 1st and 2nd are 'interesting' and so is kicking the throttle at 75mph.
I'm spinning 2400rpm at 60mph and 3000rpm at 75mph,not as bad/high as I thought they were going to be.

Tuffguy610

iTrader: (2)

So you'll be at 4000 in OD at 1000, and if you were to keep it in top gear at full throttle, you'd be just at redline as you hit 150.

FiredUpZ28

Wow. 4.56 in an auto. 4.10 seems high to me, but all my F bodys have been daily drivers

germeezy1

So let me get this straight, you are running a stall and 4.56's?

Now that is a true man, here I am thinking I am bold for running a stall and stock 3.15's...

Where does your 2nd gear top out at? Also what about 1st?

FirstYrLS1Z

iTrader: (4)

I consider it a daily driver,I also have a cavalier but don't hesitate to drive the Z(except in the winter because of the snow and salt).
It's got 117,000 on it and still running the original plugs.
I've been progressively returning to my pre-4.56 rear suspension to make sure it holds up to the increased torque the carrier and axles are subjected to(a 40% increase in torque due to torque multiplication of the 4.56s' over the 3.23s').
I first ran without the LCA relocation brackets for a few days,put on the BMR re-los and ran that way for a few days,and now I added the re-lo extensions that I fabricated and was running before the 4.56s' and everything seems OK.