Because it has a lower first gear ratio. A M29 with higher rear gears can still have the same first gear ratio as a T-56 / 4:10 combo

 

As others have said-- the slightly more agressive gearing of the M29 transmission means that 3.73's will be your best option.

Spend $200 on a set of quality gears like Strange Engineering or Motive. Don't get that whiney Richmond garbage, my Stranges have outlasted 2 previous sets of Richmonds.

You'll also need about $90 for a complete install kit from Ratech, Motive, or I'm sure there's quite a few more manufacturers. As long as its got the carrier bearings/races, pinion bearings/races, pinion seal, crush collar, both sets of shims, and a cover gasket you'll be all set.

And as its already been stated, count on about $300 for an install. It also couldn't hurt (but not necessary) to buy a $120 cover girdle which helps to strengthen the pumpkin and preload the carrier bearings. Don't forget your 2-quarts of gear oil and a little bottle of GM Synchromesh.

Don't get me wrong, nitrous done right would be a lot of fun, but gears in my opinion are one of the best modifications you can do to a 4th generation F-body.

 

Cool, great info. I'll probably try to keep the cost down and skip the cover. If I am having it installed at a shop, I don't need to purchase the install kit, correct?

 

Trust me, you'd rather buy an install kit yourself rather then pay for whatever shop's install kit you go to.

 

I paid I think $180 for a local shop to install mine and about $160-180 or so on the gears themselves, not really the common price I've seen though. most shops want between 300-500

 

Did you do them a special favor to get the price down that much? lol