There are a lot of different cost values involved. First is the choice of trans. There are many choices that will fit, with a little banging, in our chassis. The most popular are a Power Glide, TH400, 4R70w and the GM 4L80E. Then you have the choice of a manual or automatic valve body. A manual valve body is the cheapest way to go. This is basically a stick without a clutch, you have to shift each gear manually. Most of the transmissions have an option of an automatic valve body and you can have it setup with an automatic controller. Then you have the choice of a lock up converter, or a non lockup one. The non lockup setup is actually stronger because it has a solid input shaft but it generates a lot more heat because it is always slipping, so it's better for a track only car.
You will need a new flex plate, to replace the flywheel, some wiring modifications to the harness, a shifter, new driveshaft and either a trans blanket/shield or an SFI certified case. As you can see there are many options and the cost will depend on which way you go, manual or automatic and how much HP you want the trans built to handle. But the basics of what you will need will be the same. I plan on going with the 4 L80E if my 5R gives out. The 4L can be built to handle much more power then the 4R70 can and be more reliable. It's basically an upgraded TH400 with an O/D and the Th400 is one of the strongest transmissions ever built. I have seen too many 4R70 setups fail, to invest money in that setup.
