I am swapping a zr1 diff and C6 cradle into my 2002 z06, I have a set of c6 (steel frame) control arms that came with the C6 rear cradle. From what I understand the c6 control arms move the rear wheels back 5/8"? I feel I could benefit from moving the rears back about 1/2" or so due to my tire size ( tires rubbing the front of the wheel well ever so slightly). If I go with the C6 arms do I need to use both the the upper and lower in conjunction to move the wheels rearward? Or just the lower? FYI I have coil overs. I am planning on picking up a set of G-speed spherical bearings so I would probably have to get a custom set to fit the arms (C5 front and C6 rear)
Also I am planning on getting a set of G-speed solid engine and transmission mounts the rear C6 cradle has the duel pattern mounting holes will the standard mounts work or will I need to get or make a set of offset solid mounts? I am also swapping a c6 z06 front cradle into my C5 , I have the cradle but I still need to pick up a early c6 steering rack and intermediate steering shaft, any tips on doing the front swap are appreciated too.
I just got the new diff from RPM a few days ago.

 

@Tusc recently did some C6 swapping. Might try sending him a PM.

 

If you're on coilovers you can go either way fie the control arms. I don't believe the uppers matter one to another. Of note, since it sounds like you're going to track it hard is that the C5 knuckles are occasionally considered weaker on the arm to the tie rod link especially when on a car with sticky tires pushing heavy Gs. The C6 knuckles are stronger. The C7 knuckles and arms seem to be stronger still. Feont C7 knuck is a straight swap. Rear requires an FDF rear toe arm as the connection on the knuck is lateral and not horizontal, also this piece makes for easy adjustment and clears the coilovers better while clearing your end links.

Mounts...I've heard conflicting for the rear cradle. It seems as though the C6 oe connection should work. I can't say. Mine came with offsets and that's what I have used with the same later style cradle.

It also sounds like you're not afraid to mod and are seeking to push the car. You might check out Sweet Engineering. The install isn't crazy from what I have seen of others: https://sweetmanufacturing.com/home.php?cat=3

 

The car is set up for standing mile , and street driving, currently it is making 870 HP naturally aspirated I am currently pulling it apart to do a bunch of upgrades, mostly to the engine and rear diff I am shooting for close to 1000 HP on the new build. If I go with the c7 rear knuckles will the C6 brakes still mount? Currently I am running the viper ACR 355 tire in the rear.

 

Oh shoot. You are right on with that question. No. The calipers will bolt on but the radius from center will be too short. On my car i scored some AP calipers with a C7 bracket, so my fronts are C7 knuckles now.

​​​​​​However, if you run 19s in the front you could run C7 iron Z06 brakes. I am on a cp5060 caliper and offsetting it to allow use of C6Z blanks from KNS which means I can enjoy my street 19s but still run C5Z 18s.

 

Point of clarification: I believe the C6 knuckle upgrade is 09+, not all C6 years.

On the C7 stuff, do they change geometry or anything?

 

They bolt in directly from what I've seen with mine.

Except that the caliper mount holes are moved closer to hub center and the C7 caliper ears with the holes are longer. So swapping C7 brakes to a C5 they will bolt in but the center from the hub makes the rotor diam about 15.5mm so they are unusable until you install C7 front knuckles. I am unsure of the C7 rear knuckles/brake mounting points.

I actually have a C7 set of Z06 brakes here which I had test fit for fun.