Rear drum to disc brake axle swap

[Meats92-25thAnn]

I have a 92 RS with drum brakes. I blew my rear-end out and removed my entire axle assembly. I came across an axle assembly with disc brakes. I need to know what I all have to change in the car so it works properly and safely. I know that I need to change the master cylinder and proportioning valve. What I'm wondering about is the parking brake cables if I just need to change the rear cables or what goes into that. also I heard someone say that the flexible piece of line between the car and the axle needs to be changed, I'm not positive though. Also are all the fittings on the lines the same as to where they go into the master cylinder and the proportioning valve / distribution block. I'm mainly hoping that I don't have to change all of the lines in my car for this. Any information anybody can give me would be greatly appreciated. Thank you for your help.

[gear_head01]

Hey I want to do the same thing to my car too, but you dont have to change your master cylinder, I wasnt even going to change the proporting valve, is it a 5 speed or what? I dont think you have to change any of the lines, they are the same size fittings, maybe the lengths are different from the wheel cylinder apart from the caliper. are you changing just the axles or the entire rear end? You might have to change the brake hose, flexible line, but those are under 20 bucks.

[Meats92-25thAnn]

I have a TH700-R4 Auto tranny, but sometime in the future I want to install a manual. The axle I picked up has the discs, calipers, lines, and everything else that goes along with it. I just unbolted my entire axle aseembly out from under the car because I blew the gears out of it and didn't want to go through the hassle of changing them. So I found a complete axle with discs and am going to put that in my car. It's out of a late 80's IROCZ that my friend who lives in Nashville, TN found down by him. I can't really look at the car to see what's physically different. But thanks for the info any little bit helps and good luck to you on the same project. I'll be getting the axle in about a week and start the project. I'll let everyone and you know what all goes into it then because I'll know for sure. Again thanks for the help.

[zcamaro85]

it should be a pretty straight up bolt in, but the proportioning valve does need to be changed. Do you know what rear you're putting in? 9 or 10 bolt? gear ratio? what year? I picked up a 9 bolt 3.27 posi disc rear that I'll be putting in my camaro soon, probably after the paint job.

[gear_head01]

Where are you guys finding all these 9 bolt posi rear ends with disc brakes? I have never seen one in my life, I dont think I have seen a camaro with a 3.27 ratio either? I have a 9 bolt and it doesnt have posi and it doesnt have rear disc either, and its 3.23 ratio, I just gave up and bought a 10 bolt ready to go with 3.73's in it.

[zcamaro85]

My 9 bolt posi disc 3.27 rear end is out of an 89 formula that was equiped w/ a 350, and auto tranny of course, and since it's an 89, it came w/ aluminum calipers. I think the rotors may be bigger than 88 and earlier disc rear ends also. 9-bolts were optional in the 85-89 Trans Ams, and 87-89 IROC's. All 350's in those years have 9-bolts, either 2.77 or 3.27. The 3.45 ratio came in 5-speed cars with the G92 option. There is a 3.70 ratio that only came in 85-86 Trams Ams with the L69 engine and G92 option package, but they are really rare. The RPO codes will be GUx for a 10-bolt rear and GWx for a 9-bolt rear. However, the 3.70 and 3.73 ratios RPO codes dont follow this pattern. The easiest way to tell is to count the number of bolts holding your rear end cover on.