What will I need to do a 4 lug to 5 lug conversion?

 

assuming this is a FC (2nd gen RX-7) or???

Always helps if you put down the year and model of your car

 

yea its a 87 fc

 

Here https://www.rx7club.com/2nd-generation-specific-1986-1992-17/4-lug-5-lug-conversion-rear-write-up-616266/

summary
You will need:
1- spindles with 5 lugs
2- 5 lug brake rotors
3- brake pads
4- 5 lug calipers
5- Brake fluid
6- 5 lug wheels

that's essentially what you will need
the link I gave you is for the rear but you will get the idea

Most of the time you can find stuff in the faqs or in the second gen archives (just a hint)

 

That sounds about right, the whole proccess is easier than you think, that was one of the first things i did to my first RX-7 without any knoledge of these cars