Ant87IROC

IS this a direct swap or does some modification need to be done? Curious beacuse I am about to bolt up the LS1 brakes on the front soon and want to know what needs to be done to have the rear ones on also. Thanks

cam-

I too am just starting this mod. I have the car in the shop to do the C5 front and 99 Z rear brakes on my 87. I know it is a direct swap if you have a factory 12" PBR set up already but I have those crappy cast iron caliper one mounted forwardds one backwards rear brakes. I will be into this today or tomorrow so I will let you know what I find.

Ant87IROC

Thanks dude, I would love to know what the deal is. I dont have the good 89 brakes. I think just the regular 10 bolt rear disc that came with the 87 IROC and they suck.

iroc22

If you search "LS1" in the "Suspension / Chassis / Brakes" section there is A LOT of information on the swap.

Ant87IROC

everything seems to be for a rear drum swap and not disc. Not sure if disc is a direct swap without major modifications like the front disc....

ebmiller88

iTrader: (7)

Did you look in the Tech Article section of the home page??? I know you have the disc but it's the same thing except you don't have to cut the axle flange. If you have a 10 bolt, it's a piece of cake..if you have a 9 bolt, you'll have to figure out how to mount the backing plates.


http://members.fbody.com/86firebird/ls1/ls1brakes.htm

and

https://www.thirdgen.org/newdesign/t...reardisc.shtml

The hardest thing you will have to do is fab up a bracket for the e-brake cables.


Ed

cam-

Well now I am in a fickle. I have a 9 bolt form an 88 GTA in my car and the flange is quite different than the caliper braket is. This doubly sucks because the plate the holds the axle in is going to be a bugger as well. Anyone swap LS1 brakes onto an early 9 bolt? I have my car appart right now and could really use help for the "easy" solution. Best I can think is to weld on a whole new flange on the rear end. I am going to start searching all over but any tips would be appreciated. Thanks.

Justins86bird

LS1 rears should bolt right up to the iron caliper rear discs. They both share the 4 bolt flange pattern. The brake hardline will need to be modified or replaced.

ebmiller88

iTrader: (7)

I know you probably already have all your LS1 parts on hand, but for 9 bolts, I strongly recommend just swapping to the 1LE/LT1 style PBR rear brakes. It's an easier swap to do and you won't have to hassle with drilling out the backing plates or making other mods that may destroy some stock parts. 9 bolt PBR plates will bolt right in and the PBRs will perform the same anyhow. I know the LS1 rears look better, but for ease of install, the 1LE/LT1 PBRs are the way to go. Plus you won't have to hassle with fabbing up a bracket for the e-brake cables to function properly.

Ed

cam-

Well like you said I do have all the parts together for this swap and to make matters worse I have the car ripped apart in the shop so I don't want to have to start sourcing out stuff again right now. I know those "old" style work great because I have them on an 89 1LE ex Players Challenge car. If only I knew then. Anyways I started a new thread to deal with this and any help would be greatly appreciated. Thanks.

Sorry Ant87IROC I do not mean to flame. Looks like you are in for an easy ride whereas I am in for some fab fun!

coolguywalt

If swapping onto an 87 10 Bolt w/ 4WD brakes, will I need any shims of any sort to get the caliper to be centered above the rotor correctly?

91rsv6

Ive done the swap it was pretty strait forward. I havent got the e brake bracket made yet so no e brake. but the hard lines just took alittle persuasion to bolt up. I braking increase was slight but noticeable. cant wait to try get c5 setup for the front. but c5s and 17" are expensive so paint and first thing to break is next on the list.