[Onecent]

I'm looking in too a 96 Formula Firebird 5.7 long tube headers, with 3in exhaust , cam, 150 HP wet shot of nitrous, 4 10 gears with superior axles, new front and rear struts , Brakes, tires ,nice car.. really nice .
My question is it worth buying w 4 10 gears of I wanna drive daily & cruze? Probably won't be using the nitrous

 

[Injuneer]

Depends whether it's a T56 (6-speed manual) or a 4L60E (4-speed automatic).

The 4.10’s go very well with the T56 because of the steep overdrive 5th (0.74:1) and 6th (0.50:1) gears. Still be loping along at reasonable RPM in 6th gear on the freeway. The 4L60E likes a set of 3.73’s better, with the 0.70:1 O/D 4th gear.

Interesting they only upgraded the axles. The 10-bolt rear carrier with the 7.625” ring gear is the weak point. Heavy mods + N2O + sticky tires will break things up.

 

[GaryDoug]

Uh..it sounds like you like to quote the racy features. Are you sure that's what you want for street driving? I would.... but then I am insane ;-) Also, INTO is one word!

 

[Onecent]

Well it an Automatic. I don't have a need for the N20. Haha I mean it badass.. love the speed. Lol. It does have original 18,000 mils. $6,000.00

 

[sleepyhollowtaman]

Depends whether it's a T56 (6-speed manual) or a 4L60E (4-speed automatic).

The 4.10’s go very well with the T56 because of the steep overdrive 5th (0.74:1) and 6th (0.50:1) gears. Still be loping along at reasonable RPM in 6th gear on the freeway. The 4L60E likes a set of 3.73’s better, with the 0.70:1 O/D 4th gear.

Interesting they only upgraded the axles. The 10-bolt rear carrier with the 7.625” ring gear is the weak point. Heavy mods + N2O + sticky tires will break things up.

Yes it works in 6th gear but, 1st gear will be worthless. You will be shifting way to fast. With the stock rear gear you cruise 1800 at 80 mph. I would put a 3.73 gear in it. Even with a 4L60 I wouldn't go steeper than 3.73

 

[Injuneer]

I'll have to disagree, other than the fact the RPM with stock setup is 1,800 @ 80 MPH. My spreadsheet for the T56 with stock 3.42 gears shows 1,793 RPM @ 80 MPH.

With the stock tire diameter/3.42 rear, shift points at 5,800 RPM:

1 - 48 MPH
2 - 72 MPH
3 - 99 MPH
4 - 129 MPH

Throw in a set of 4.11's:

1 - 40 MPH
2 - 60 MPH
3 - 82 MPH
4 - 107 MPH

Where is the problem?

OK... if you're running 110+ MPH in the 1/4-mile you get forced to shift into 5th O/D. Although most likely to run that MPH you would be shifting a modified engine higher than 5,800 RPM.

Don't confuse the 1994-2002 T56 (2.66:1 1st gear) with the 1993's two T56 options, RPO "M28" 3.36:1 first gear, or "M29" 2.97:1 first gear. The 93's would turn into stump pullers with 4.11's.

I swapped in a Strange 12-bolt with 3.73's. Even with a slightly modified LT1 engine that was happier at 6,000+ RPM the 3.73's were disappointing. 9% more grunt with the 3.73's can't come close to the 20% extra with 4.11's.

And, I believe I already indicated that 3.73's are preferable for most 4L60E owners.

 

[Onecent]

Well car got sold, before I could even go to Iowa. So oh well. Sounds like just wasn't meant to be haha

 

[ZumpTA]

Don't confuse the 1994-2002 T56 (2.66:1 1st gear) with the 1993's two T56 options, RPO "M28" 3.36:1 first gear, or "M29" 2.97:1 first gear. The 93's would turn into stump pullers with 4.11's.

Before YouTube existed, there was an auto-centric video sharing website called StreetFire.Net. There was a guy I was subscribed to with a "bolt-ons" '93/M29 and 4.11's. His thing was completing the 1/4 before an import could cover the 1/8th. Never got old watching the import start from halfway up the strip, only to be passed in the last second by the T/A. ...good times!