... and why you see 84 not included in some aftermarket brakes applications. See below.



As you can see the 84 knuckle on the left has smaller mounting holes for the caliper bracket and less "meat" around those holes as well than does the 85 knuckle on the right. When I rebuilt my 85 car... I had all the 85 Z51 suspension pieces except the front knuckles. They came off my 84 parts car I had. Well, I decided to upgrade my brakes and found that my options were very limited if I kept the 84 knuckles on the car. I decided to put the correct knuckles on the car ($175 later) and upgrade the brakes to C5. I'll post pics of that in another thread but just wanted us early C4 forum guys to know why we see 84's left out in many front brake upgrade kits. Although there are aftermarket kits for the 84 in talking with VetteBrakes at their tent last year at the Route66 car show here in Phoenix they felt the 84 knuckle was just too weak to support bigger brakes. I have not talked with Gene at Electro-Dynamics but currently his published product line does not support the front brakes of an 84 either. Just for giggles I tried to bolt one of his adaptors to the 84 knuckle... and his supplied bolts are just too big. And NO I would NOT even begin to support, nor will I even suggest, trying to bolt his adaptors to an 84 knuckle with smaller bolts. Anyway, thought you earlier C4 guys might like this tidbit of info :)

:cheers:

 

A fascinating insight into GM Engineering foresight...I wonder how many cars were damaged to prove that engineer wrong...

("But, look - my mathematical calculations prove it will hold!!!")...

I'll wager that if you put grade 5 bolts into an Electro-Dynamics big brake upgrade kit and slammed the brakes on at 55, you could shear both bolts clean off...Maybe even grade 8 bolts...

...I imagine it has happened already even without big brakes...