I think it will be a big difference compared to the 3.42s that I have right now, what do ya'll think?

How will more gear affect me as far as racing goes on the highway? I mean like from a roll going like 45-60mph? Would the 3.90s help me just out of the hole or both low speeds and high speeds?

Where is the cheapest place to get everything? I called Tom's Differentials last year and this is what they told me everything would cost:

Eaton Posi = ~$320
GM Gears = $150
Installation Kit = $100

It sounds reasonable. If there is any place cheaper please let me know.

Thanks in Advance.

 

I have the 3.90s in and it made a huge difference in the way the truck performs. Yeah, you're gonna lose some up high, but if you race from a 20 roll it helps. I cruise around 2100 at 70mph. And 3rd pulls a lot better.

 

If you are concerned about highway racing, just go with some 3.73's. You will like those better. That is one sweet deal on the GM gears. I got mine for $200 for my 01 Sierra.

 

Would the 3.73s be a big difference over the crappy 3.42s I have now? The thing I hate about the 3.42s is, they pull hardest the first half of 1st and 2nd gear. They start pulling about half-way through the gears. I'm talking about from a roll. At the track after about 2500rpms or so, they pull hard until I hit 3rd gear. The top-end at the track is great (shifts into 3rd ~92-94mph), it just feels like it could be reving faster. So could 3.73s be the answer to my problems and still let me keep a little bit of my top-end? Thanks for the input guys!

 

The lower gears will help you across the board, especially in third so I would stick with the original plan of 3.90. I have 3.73 and offten wish I had just a little more gear. Since you dont have a converter, I think the little more gear would be even more benifical to you.

 

So would less gear be needed with a converter? I have often thought of staying with my 3.42s and just putting an Eaton in.

 

The converter gets the engine up closer to that sweet spot quicker. That's the only reason he said something about the converter.

 

Thanks ya'll. I think I'm gonna go with the 3.90s.