ron, you do not have to buy a new valvebody for a full manual forward pattern. all you need is a transgo manual valvebody kit. there are differant kits depending on the year. you can not make a "green dot" 64-68 valve body into a fwd manual.
the kits are not too difficult to install, and any transmission mechanic should be able to install one for you.
some disadvantages to a fwd pattern.
pm me if you need help-rich