MitchV

My '93 has auto trans with the 2.59 rear gear. It's a great car, but a turtle off the line. My understanding is that the performance axle, 3.07 offered for '93 requires the Dana 44 and to swap the Dana 44 into my car would require changing the C-beam, driveshaft and batwing. What type of performance gain can I get using my current Dana 36 and changing to new 3.54 (thick) gears?

WVZR-1

The 3.07 was also offered in a D36 for most years. I'd prefer a 3.07 OE/GM build I believe vs a 3.54 build of a 2 series case. Unless you had a reason to want/need the 3.54 I'd shop hard for a D36 3.07. They're around but likely expensive.

You DO NOT need the D44 to get a 3.07 ratio.

NOMOREWORK

I just found one on E Bay for my 89 paid $300 for center section.

Silver85

I found several for $500 with the 3.07 gear.

What are your plans for the car? Mine is a weekend cruiser and the 3.07 is a pretty good compromise for decent off the line and tolerable for long trips. I would definitely want something more if I wanted straight line speed though.

LUDS 96

About .5 seconds in the 1/4 if you come out hard with sticky tires. I have this set up in my car.

vader86

You do not need the D44, but it depends how much youre going to race the car and what tires you want to run on it. If you want DR slicks, better buy the 44. The 36 might last a little while, but it will go whenever it feels like if that is your plan.

They do make 3.54 gears for the 2-series case D36s as well.

vette196

D36 with 3.07 rebuilt about $500 on ebay. I got one for about half (not rebuilt) that I plan on installing this winter

MitchV

My car is a summer driver, about 2,000 miles a year. I've driven a '95 LT1 with 3.07 rear gear. While MUCH quicker off the line than my 2.59, I thought while I'm making a rear gear change, why not go to a 3.54. I'm not going to race my car, it has street tires and no engine mods. However, I haven't driven a LT1 with 3.54 gears. Is there a big performance difference between 3.07 and 3.54?

psychodiagnostik

Like others have said, you can probably find a D36 that comes with 3.07 already, for 400-500$ on ebay. Aftermarket gears for D36 with the 2 series carrier (what you have) are pricey, at ~ $400 for just the ring & pinion, and you'll need some other parts and labor for a professional install into the housing.

You might even find a D36/3.07 locally on Craigslist, sometimes people part out C4s and you can get decent prices on stuff like complete diff assemblies.

I picked up what I thought was a complete Dana 36 with 3.07 setup locally for $120 off Craigslist, however once I took it apart & cleaned it up I found it has a USGear 3.73. But haven't tried it out yet, so who knows if it works well.

TA

Are you planning on tracking it a lot and what tires are you using. If you're sticking with street tires a D36 will be fine. If you plan on getting to the track often and using drag radials, you should probably consider a D44.

Fastnail

The 3.54 rear makes a difference off the line, but will hurt your mileage in the long run. I went from a 3.07 to the 3.54 and it was a good choice for the track, but I prefer the 3.07 for the street. Good luck with it.

MitchV

I'm looking for more "go" off the line. No track use. Just stop light to stop light driving and occasional highway use. How different are your rpm's on the highway, 3.07 vs 3.54? Thanks.

Boss Lady

On my 93, I changed the 2.59 stock gears with the Yukon 3.54 thick gears and cruising at 85 mph went from 1,900 rpm's to 2,650 rpm's. I really like the change! After the gear swap, I installed long tube headers (American Racing) and they actually seemed to give me more in the SOP over the gears. Maybe it was just a great compliment to the gear mod.

SuperL98

If you want to see if you can live with the 3:54 gears on the highway, just leave your shifter in 3rd gear (with the 2.59) and test drive it down the highway.
It is about the same as your overdrive would be with the 3:54 gear.

2.59 x 1 (3rd gear) = 2.59 overall ratio

3.54 x 0.70 (4th gear-overdrive) = 2.48 overall ratio