Changing the overdrive in a t5?

[91CoupeMike]

I was looking into changing the 5th gear in one of the t5s I have. From what I've gathered, 5th gear can be changed from .68 to .73, .80, or 90. .63 can be changed to .59, .73, or .83.

I'd like to find a .73 gear set for 5th, because that should run the best.

Where would I find this? What kind of $ am I looking at? It'll be going behind a h/c/I 302.

[greenbullitt]

a core trans! or standard trans/gear. some turbo coupes had a .79

[91CoupeMike]

a core trans! or standard trans/gear. some turbo coupes had a .79

If I were to buy the turbo coupe 5th what all is interchangeable? Would I just need the drive and driven gears?

5th is like an add on correct? From looking at it, it looks very simple to change 5th.

.79 is a bit steep too though.