I know for the front ill have to use LS1 spindles am I going to need to change anything on the back to switch to C5 rear brakes?

 

The C5 rears have parking brake in the rotor hat, just like the LS1 F-bodies which are for all practical purposes identical. The backing plates and mounting brackets are also different. There's probably a slight length change for the ls1 axles too, to accommodate the backing plate.

 

You can use your stock spindles with the C5 bracket.
You will have to cut the ears off, but you need to do
that with the LS1 spindle also. (Talking about the front)

 

awesome thanks for the advice