87 10 Bolt rear with 91 Disk backing plate - Third Generation F-Body Message Boards

Go Back  Third Generation F-Body Message Boards > Tech Boards > Brakes
Reload this Page >

87 10 Bolt rear with 91 Disk backing plate

Brakes Looking to upgrade or get the most out of what you have stock? All brake discussions go here!

87 10 Bolt rear with 91 Disk backing plate

Old 03-04-2018, 10:06 AM
  #1  
Supreme Member
Thread Starter
 
Kevman's Avatar
 
Join Date: Jul 2006
Location: Windsor Ontario
Posts: 1,672
Car: 1987 Firebird Formula
Engine: 2004 LQ4
Transmission: T-5 WC
Axle/Gears: 3.42
87 10 Bolt rear with 91 Disk backing plate

Hey guys, I've tried searching, I have an 87 10 Bolt all rebuilt that came with my Formula, and over the years I've collected parts I knew would be difficult to find until I purchased another ThirdGen, but I have a set of 91 Rear disk backing plates, can the axle flange be modified to fit the backing plate?

I want to upgrade to 28 spline axles, and a new carrier, so if the axles will not work, it's not a big deal.
Kevman is offline  
Old 03-04-2018, 10:18 AM
  #2  
Supreme Member
iTrader: (6)
 
TTOP350's Avatar
 
Join Date: Oct 2001
Location: central Il USA
Posts: 9,888
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: 87 10 Bolt rear with 91 Disk backing plate

91 backing plates will bolt right on the 87 10bolt.
TTOP350 is offline  
Old 03-04-2018, 10:22 AM
  #3  
Supreme Member
Thread Starter
 
Kevman's Avatar
 
Join Date: Jul 2006
Location: Windsor Ontario
Posts: 1,672
Car: 1987 Firebird Formula
Engine: 2004 LQ4
Transmission: T-5 WC
Axle/Gears: 3.42
Re: 87 10 Bolt rear with 91 Disk backing plate

Originally Posted by TTOP350 View Post
91 backing plates will bolt right on the 87 10bolt.
Even though the 87 flange is for a drum?
Kevman is offline  
Old 03-04-2018, 11:12 AM
  #4  
Supreme Member
iTrader: (28)
 
Drew's Avatar
 
Join Date: Jul 1999
Location: Salina, KS
Posts: 17,121
Re: 87 10 Bolt rear with 91 Disk backing plate

No. Easier to get the "hassle-free" brackets from Fly-n-bye.

Otherwise you have to cut, drill, shim, and concentric ring the drum rear.
Drew is offline  
Old 03-04-2018, 11:41 AM
  #5  
Supreme Member
iTrader: (6)
 
TTOP350's Avatar
 
Join Date: Oct 2001
Location: central Il USA
Posts: 9,888
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: 87 10 Bolt rear with 91 Disk backing plate

Originally Posted by Kevman View Post
Even though the 87 flange is for a drum?
Since it wasn't mentioned, I incorrectly assumed the 87 rear was a disc also.

I have cut and drilled to flange to make disc work on a drum rear b4. However, Drew is correct, the bolt on backing plates work very well. Used them a few years ago.

If you are interested in selling the 91 disc backing plates to offset the cost of the bolt-on brackets , let me know, may be interested .
TTOP350 is offline  
Old 03-04-2018, 12:17 PM
  #6  
Supreme Member
Thread Starter
 
Kevman's Avatar
 
Join Date: Jul 2006
Location: Windsor Ontario
Posts: 1,672
Car: 1987 Firebird Formula
Engine: 2004 LQ4
Transmission: T-5 WC
Axle/Gears: 3.42
Re: 87 10 Bolt rear with 91 Disk backing plate

Originally Posted by TTOP350 View Post
Since it wasn't mentioned, I incorrectly assumed the 87 rear was a disc also.

I have cut and drilled to flange to make disc work on a drum rear b4. However, Drew is correct, the bolt on backing plates work very well. Used them a few years ago.

If you are interested in selling the 91 disc backing plates to offset the cost of the bolt-on brackets , let me know, may be interested .
Yes, I would be interested in selling them if I cannot after all use them. PM me, and I will dig them out of my shop.
Kevman is offline  
Old 03-04-2018, 03:35 PM
  #7  
Supreme Member
iTrader: (28)
 
Drew's Avatar
 
Join Date: Jul 1999
Location: Salina, KS
Posts: 17,121
Re: 87 10 Bolt rear with 91 Disk backing plate

You can modify the drum flange to use the disc mounting plates, it just takes more effort than the aftermarket bolt-on mounting plates.

AndyZ28 offered the parts, but his website is currently down, and they cost as much as the no-hassle adapters from Flynbye. I'm in the same boat at the moment, NOS 91-92 backing plates, and a drum rear. Not sure which way I want to go yet.

These shots from the AndyZ28 1LE CD show what has to be modified.












Drew is offline  
Old 03-04-2018, 10:16 PM
  #8  
Moderator
iTrader: (5)
 
JamesC's Avatar
 
Join Date: Aug 1999
Location: Lawrence, KS
Posts: 19,095
Car: Met. Silver 85 IROC
Engine: 350 HO Deluxe (350ci/330hp)
Transmission: T-5 (Non-WC)
Axle/Gears: Limited Slip 3.23's
Re: 87 10 Bolt rear with 91 Disk backing plate

The following 10-Bolt FAQ has a lot of info on brakes, to include the drum/disc axle interchange, master cylinders, combination valves, e-brake cables and so forth:

https://www.thirdgen.org/forums/tran...-10-bolts.html

After modifying the flanges, the following conversation write-up should prove somewhat useful:

https://www.thirdgen.org/forums/faq-...iscs-89-a.html

JamesC
JamesC is offline  
Old 03-05-2018, 10:01 AM
  #9  
Supreme Member
Thread Starter
 
Kevman's Avatar
 
Join Date: Jul 2006
Location: Windsor Ontario
Posts: 1,672
Car: 1987 Firebird Formula
Engine: 2004 LQ4
Transmission: T-5 WC
Axle/Gears: 3.42
Re: 87 10 Bolt rear with 91 Disk backing plate

That Fly N Bye performance is dangerous for my bank account.

For $84 USD I can get the kit for 1LE brakes, so I may sell the ones I have and go that way.

I also discovered they sell the hubs and caliper mount for 2010 Camaro SS front rotors, which with my parts store discount could be worth while.
Kevman is offline  
Old 10-28-2018, 04:56 AM
  #10  
Senior Member
 
Join Date: Sep 2005
Location: Windsor, Ontario
Posts: 505
Car: 1987 Trans Am
Re: 87 10 Bolt rear with 91 Disk backing plate

Originally Posted by Kevman View Post
That Fly N Bye performance is dangerous for my bank account.

For $84 USD I can get the kit for 1LE brakes, so I may sell the ones I have and go that way.

I also discovered they sell the hubs and caliper mount for 2010 Camaro SS front rotors, which with my parts store discount could be worth while.
Hey Kevman, I am local to you and have a lathe and bridgeport in my home shop. I can probably save you a bit from ordering from the states. Cheers!
I can make hubs etc. I have an 87 T/A myself.

Last edited by rgauder; 10-28-2018 at 05:02 AM.
rgauder is offline  
Old 10-28-2018, 03:40 PM
  #11  
Supreme Member
iTrader: (6)
 
TTOP350's Avatar
 
Join Date: Oct 2001
Location: central Il USA
Posts: 9,888
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: 87 10 Bolt rear with 91 Disk backing plate

Originally Posted by Kevman View Post
That Fly N Bye performance is dangerous for my bank account.

For $84 USD I can get the kit for 1LE brakes, so I may sell the ones I have and go that way.

I also discovered they sell the hubs and caliper mount for 2010 Camaro SS front rotors, which with my parts store discount could be worth while.
Let me know about the factory backing plates
TTOP350 is offline  
Old 10-28-2018, 04:50 PM
  #12  
Senior Member
 
Join Date: Sep 2005
Location: Windsor, Ontario
Posts: 505
Car: 1987 Trans Am
Re: 87 10 Bolt rear with 91 Disk backing plate

Originally Posted by TTOP350 View Post
Let me know about the factory backing plates
I think this is what he is talking about:

http://www.flynbye.com/catalog/i30.html
rgauder is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
billy050302
Brakes
6
05-13-2010 06:19 PM
1 DwnCam
Transmissions and Drivetrain
7
05-14-2006 06:20 PM
91banditt2
Brakes
21
03-10-2006 02:48 PM
Z28ricer
Transmissions and Drivetrain
3
02-18-2001 11:16 PM


Thread Tools
Search this Thread
Quick Reply: 87 10 Bolt rear with 91 Disk backing plate


Advertising
Featured Sponsors
Vendor Directory

Contact Us Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: