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AWDPete
09-14-2013, 06:04 AM
I'm in the stage of my build where I need to decide what to do with the rearend in my '68 Camaro. I will be going with a CW 4-link. My question is in regards to the rear axle itself. I currently have a 12-bolt with a good posi but with 4:56 gears and stock axles. It will have 625 hp at the crank. Looks like my options are: build the 12-bolt or go 9 inch. I have been hearing stories about noisy 9" gears and diff probs which makes me a little leary of going that route.

The other question is when does going to a floater make sense?

The car will be driven to events, auto X, road course, drag strip, etc. It will get used.

Todd in Vancouver
09-14-2013, 09:13 AM
I'm in the same boat as you with a 12 bolt for my '67. I've got my local rear end guy fixing me up and here is what I've got happening for about $1K.

Shorten my axle tubes to allow for bigger wheels and fit my mini-tub
Install big Ford axle bearings for a full floater set up
Weld on all my brackets for my TCI torque arm suspension (while in the jig so its straight)
Note: I'm tacking the brackets in place
Install new axles to fit the shortened diff

For gears I'm going with 4.11:1 or 3.91:1 as I've got a TKO with a .64 overdrive in 5th. Just do the math first before you commit to a gear ratio and I've got it figured to a great cruise RPM @ 65mph. Just need to make the final decision on 18" or 19" rear rims.

Good luck and I say go with the 12 bolt IMO.

AWDPete
09-14-2013, 12:12 PM
Thanks for the reply Todd.

Who's floater kit will you be using? As I understand it people are using the floater kit to cut down on brake pad knock-back and longer service intervals on outer bearings. Is that about right?

Stock GM posi or?

Looks like I can stick with the 4:56 if I go with the 2.97 - .50 ratio T56 Magnum or down to a 3:73 with the close ratio 2.66 - .63 T56. The close ratio box doesn't have as big a jump in the upper gears. A 70 mph pull from 5th to 6th would be tough!

I just checked out your build thread - it's coming along nicely! And your car looks to be the same OEM color as mine!

TheJDMan
09-15-2013, 02:37 PM
Install big Ford axle bearings for a full floater set up

Wait What? You don't install big Ford axle bearings if you want a full floater you weld snouts on the axle tubes.

Todd in Vancouver
09-20-2013, 07:33 AM
Sorry you are correct Steve in that they are welding on new ends of the axle tubes. It's an elimination of the C-clips I was thinking of.

XLexusTech
09-20-2013, 07:56 AM
Note.. please learn form my mistake.. make sure you know exactly what rotor your going to use before you order axles.. otherwise you end up with brakes that don't work with the axle register or hub that nobody will equped to cut.. (hardened and axle is long for std lathe) :-(