Anyone retro fitted a close ratio gearbox?

[chris watton]

Talking to a friend of mine last night, he was telling me how good the close ratio box was in terms of acceleration was compared to the normal box.
Has anyone ever had a close ratio box fitted, or replaced the normal box with one, if so, how much, and would you have to pay full price if your standard box was kept by the guys who fitted the new one?
just a thought

Chris