200r4 is a smaller, weaker version of 700r4. It was used in 4 cylinder and 6 cylinder cars and mini trucks, while the 700r4 was used in anything full-sized or v8 equipt. Sure, you can build a 200r4 to work for your application, but it will be cheaper to buy a 700r4 that is come strong enough from the factory. If I had a lot of money, I would keep the turbo350 and buy a add on overdrive; it's only $1700 if I remember.