rear brake upgrade

[deanlemans81]

Ok guys, here`s a question for you. At work today I changed the rear brakes on a 98 4wd blazer with discs front and rear. I know about the front brake upgrade using 2wd blazer parts but whenever someone does a rear brake upgrade, most often they use 4th gen ls1 f-body parts. Why not use the rear disc brakes from the same blazer that gives you the fronts? The park brake set-up looks like it would be an easier swap since the cables seem to have a similar orientation with the park brake unit inside the rotor, drum brake style. the caliper is aluminum so less unspring weight and the proportioning valve would be perfectly calibrated.

Has anyone tried this? Will the backplates bolt up to a 7.5 or 8.5 diff? What do you all think?
deanlemans81

 

[RollinSlow84]

I've been looking into this but haven't found a set at the junkyards yet. The 4wd Blazer rear disk is a popular option with the second generation Camaro guys because it will clear a 15" wheel. When I do find a set, I'll post some info here and maybe make my own thread with pictures and stuff. I'm more interested in this setup because I want to keep my steel wheels. They will clear 15" wheels, I'm going to try to make it clear my 14" steelies.

I found a few threads on it and it looks like it will work but need the same mods to the housing as the LS1 type backing plates. Cut and drill two holes. The LS1 plates fit the Camaro housings and so do the Blazer plates, so I assume it will fit our ends too.

Here are a few threads on the Camaro sites,

http://www.nastyz28.com/forum/showthread.php?t=94303

http://www.nastyz28.com/forum/showthread.php?t=109454

 

[L92 OLDS]

I found a few threads on it and it looks like it will work but need the same mods to the housing as the LS1 type backing plates. Cut and drill two holes. The LS1 plates fit the Camaro housings and so do the Blazer plates, so I assume it will fit our ends too.

The LS1 rear brake swap is nice option but will NOT clear all 15" rims. I installed an LS1 setup on a spare rear end and the caliper brackets hit my factory SSIII rims. On to plan B.

I've looked at the blazer rear disk set up but it looks to me like the whole assembly is too far inboard. I think the back of the calipers will hit a G body frame. Luke (83Hurstolds) has also mentioned this in a few of his posts.

 

[RollinSlow84]

I found a few threads on it and it looks like it will work but need the same mods to the housing as the LS1 type backing plates. Cut and drill two holes. The LS1 plates fit the Camaro housings and so do the Blazer plates, so I assume it will fit our ends too.

The LS1 rear brake swap is nice option but will NOT clear all 15" rims. I installed an LS1 setup on a spare rear end and the caliper brackets hit my factory SSIII rims. On to plan B.

I've looked at the blazer rear disk set up but it looks to me like the whole assembly is too far inboard. I think the back of the calipers will hit a G body frame. Luke (83Hurstolds) has also mentioned this in a few of his posts.

We know the LS1 swap will NOT clear all 15" wheels without major caliper grinding, it's been discussed several times on the forum. That is why the Blazer disks are being used by the first and second gen Camaro guys, so they can keep their 15" steel rally wheels. I was comparing the mounting of the LS1 and Blazer backing plates, theyre both a direct bolt on into the Camaro housing. So it seems it should work on ours similar to the LS1 mods required.

From the research I've been doing, it seems that there are two types of backing plates. The 4WD puts the caliper towards the front. The 2WD backing plates has the caliper towards the rear. I havent got my hands on any of the hard parts yet so I don't know if it'll work or not. I havent seen anymore than one thread on our forum mentioning this option and only one post about the frame clearance issue.

Have you physically bolted up the Blazer rear set up? Any pictures?

 

[L92 OLDS]

From the research I've been doing, it seems that there are two types of backing plates. The 4WD puts the caliper towards the front. The 2WD backing plates has the caliper towards the rear. I havent got my hands on any of the hard parts yet so I don't know if it'll work or not. I havent seen anymore than one thread on our forum mentioning this option and only one post about the frame clearance issue.

Have you physically bolted up the Blazer rear set up? Any pictures?

X2....Someone please bolt one up and verify caliper clearance. BTW, The Blazer issues have been discussed on other forums.

Quote:
These should have no issues fitting an A-body or F-body... however, they have a fairly deep offset and will most likely hit the frame on a lowered G-body. I have heard people say they clear on a G-body, but don't get mad at me if you try and they don't"

Here's the link.

http://www.oldspower.com/vb/showthread.php?t=60862

 

[deanlemans81]

Ok so I`m not totally out there in thinking this might work. I`ll have to try and check out some parts books at work and see if I can get more info.
deanlemans81

 

[axisg]

[I've looked at the blazer rear disk set up but it looks to me like the whole assembly is too far inboard. I think the back of the calipers will hit a G body frame. Luke (83Hurstolds) has also mentioned this in a few of his posts.

This is the same information I came up with and because of conflicting reports I pulled the trigger on the LS1 setup. What I found interesting is the 4wd trucks have a different wheel offset ( 4wd wheels are further out ) and you would think that would actually help with frame clearance reather than mentions of making it worse. Both setups can be re-drilled and clocked at either 3pm or 9pm ( to keep the bleeder pointing up ) but they will contact the frame with soft or lowered suspension. For example: collectively between 4 freinds we have all installed the LS1 rear brakes on each of our gbodies now. We installed new springs and bumpstops because the caliper will contact the frame under heavy load. In my car we removed the shocks & springs and then compressed the rear as much as possible by lowering the car onto jackstands under the axle. With the weight of the car on the orig bumpstops I could not slide my little finger between the caliper and the frame. New bumpstops is added insurance to keep everything in place. Lowered cars will make contact unless frame notch surgury is performed.

Both setups should would. The LS1 setup confirmed will work but the parking brake is a PIA

 

[deanlemans81]

I can confirm one thing for certain, the offset on 2sd and 4wd blazers is different by about 1 inch. On the blazer I did, the axels stick out 1 inch farther out that a 2wd version. I was originally given rotors for a 2wd by mistake. The difference in offset is made up with the rotor hat. On 4wd models it`s 1 inch deeper.
deanlemans81

 

[L92 OLDS]

I can confirm one thing for certain, the offset on 2sd and 4wd blazers is different by about 1 inch. On the blazer I did, the axels stick out 1 inch farther out that a 2wd version. I was originally given rotors for a 2wd by mistake. The difference in offset is made up with the rotor hat. On 4wd models it`s 1 inch deeper.
deanlemans81

Are suggesting that a 2WD rear blazer is preferable?

 

[malibu80]

I've done this swap on my 8.5 using the 2wd Blazer set-up. The caliper will hit the frame. The frame will need to be notched. Haven't installed rear into car yet. I did consider the LS1 rear brake swap but didn't like how the parking brake was set up.