hey all

just asking on behalf of a mate - hes got a stg 3 crow cam & chip to throw into his 5-speed EF. now hes been told to get a vernier gear - which he wants to do. the question is, do we just need the gear, but also the crank gear/timing chain as well? cause thats quite a bit more $$$, so is it worth buying it? any help would be much appreciated!

cheers