I picked up a 9 bolt rear with 3.08 gears (open) and want to install some LS1 brakes. I don't know how I didn't notice the difference in axle flanges.

Can my 9 bolt w/ drum brakes be modified to fit the LS1 backing plate?

 

not familiar with that flange but I assume it has the bearing and seal retainer plate right? Got any pic`s?

 

I will pop the drums off and take some pix as soon as I get home.

 

I finally got aroung to getting the drums and backing plates off. Here is what the flange looks like. All 4 bolts holding in the axles are 5/8. What mesurements do I need? Do they make new bearings and races for 9 bolts?

Also, the name of the thread is misleading. I have 2011 SS Brembo's.

 

You can get new bearings for the 9 bolt, but the axle seals are hard to get right since they are LH/RH, not the same like a 10 bolt. I bought some no name ones a few years ago. From what I have read here most of the time you will get two of the same side since the other side isn't made anymore or something. I will be re-sealing a 9 bolt in the next few weeks so I can swap out a 10 bolt drum rear.

Since all 4 bolt holes are already there you should be able to adapt any 10 bolt backing plate to the rear. I did it years ago by swapping the plates left to right so the holes did not overlap and then re-drilled for the 9 bolt pattern, but that picture makes it look like the 10/12 bolt pattern, so you may be able to get it to work without doing anything. Without measurements it is hard to tell. You will probably have to trim the drum bracket part off the flange though