well im looking into a performance 5 or 6 auto trans any suggestions and prices installed?

 

what isthe least expensive mod a tranny 2002 3.8n/a shift kit or overhaul

 

Shift kit would be the cheapest if you're going N/A or S/C. If you're going turbo then an overhaul of the trans and replacing the weak trans parts to support the mod would be a must. As far as the manual trans for an 02 Monty the OP may want to look around on line for that kind of conversion. It's a very expensive and complex procedure, with lot's of room to mess up. I only know of one person who has done this manual trans conversion and, according to him, it was a very expensive mod.

 

Yea, the manual trans conversion is not really much of an option for MOST people.

Getting a 5 or 6 speed auto really is not much of an option either...in fact I don't know of any 5 or 6 speed autos that will bolt up in place of the 4T65E tranny you already have.

Your best option is to build your current 4 speed to handle extra power (they are actually really good trannies if built correctly), and tune the tranny for specific shift points to get a little more out of it.

 

Why? What is wrong with your stock transmission? There is no trans that is going to be just a simple bolt in, plug in other than your stock tranny or similar. Not to mention, the only advantage of the higher gear # transmissions is so they can make the engines with a higher peak horsepower and higher peak torque, but with a much more narrow powerband. Since your engine was designed for the 4 speed with a fairly broad usable powerband, it doesn't make a ton of sense to add a bunch of extra gears. Plus, your stock transmission can handle plenty of power- you can build them up quite a bit if need be.

What are you asking here? Obviously a shift kit is way cheaper- the actual parts for the spacers can be had under $5, and you can reuse your stock gasket and fluid.

However a shift kit and an overhaul kit are for two totally different purposes. The shift kit is for alterning shift behaviour, an overhaul kit is meant to restore a used transmission to new.