need advice and possible part numbers

[webartie]

I have a 98 spec teg box. it has the 4.7 fd. but only on first three gears, third to 4th is not great, id like to lower 4th. i have to told to just buy a 96 spec teg fourth gear set or an ek9 fourth gear set.

is this all ill need and part number's please

thanks