Re: JL-8

[1969 Mach Five]

I searched many times in the threads here but was unable to find conclusive evidence on what it takes to convert to JL-8. I'm doing one now (not factory, just an upgrade), and thought I'd share how it's going.
For the front I have the new JL-8 brackets (available from many suppliers) coming, and J-56 calipers on disc brake spindles with Corvette rotors. For the rear I have just ordered longer axles (I don't wanna post the length until I'm sure they will work-no misleading). I'm getting my 12 bolt back soon. The rearend has been modified with larger flanges. I have a set of factory Corvette rear caliper brackets, dust shields with parking brake, and a set of Corvette rear rotors and J-56 calipers. I have mocked some of these parts and they seem to be fine.
Does this seem right to everyone else?
Or can anyone give me the link to the thread that says exactly what is required... thanks!

[Donovan]

I'm stuck half way in this conversion too, because my car is apart. I did notice however that the front brackets being sold right now place the caliper about 1/4" too far out so that the pads overhang the rotor edge. Mock yours up and check. I'm still contemplating either notching the mount holes to slide it in or getting aftermarket true 12" rotors.

the rest of what you describe sounds about right. Although I'm not sure why you need short axles? Seems like you just put the flange where you need it when converting.

[1969 Mach Five]

Sorry I meant longer axles (corrected). According to the assembly manual that is as per factory. Everything seems to be fine, and I will check the front calipers when I get the brackets. I'm still surprised nobody has documented this yet. If this all works out okay I'll take some pictures and explain what is needed in the conversion. I will check the rear final today and post my results, and I'm still waiting on axles. Any help would be appreciated!

[Donovan]

I was under the impression that the axle length issue mentioned by the factory was due to the fact that they were converting big car 12 bolts to jl8. Definitely double check the rear setup
Definitely take pics and post a how-to.. It'll be fun.

This is not a common swap because the vette calipers have an undeserved bad reputation. It's also a heavy and complicated swap, most folks just go PBR.

I wanted to do this swap because it is 4 wheel discs that have a large variety of choices in pad/rotor, the parts are available at any parts store anywhere and the setup is correct for the era, so it keeps the theme of the car in my opinion. Lastly, another thing that is unusual here, I wanted to keep 15" wheels! This is the only setup that doesn't have the stupid integrated lever parking brake and fits 15s

[1969 Mach Five]

All factory JL-8 rear ends used the larger passenger car housing ends and the larger bearing size. I am doing mine this way also. Like I said, I'm doing my conversion as per factory. I got my 12 bolt back and did some mock-ups at my local rearend shop. The shop did a good jod in the conversion, but it was expensive and not perfect. I will need to run spacers to get the rear caliper alignment correct. I don't know why more people aren't doing this conversion, or why nobody really seems to know much about what's involved. I think the later model floating PBR calipers are cheap and lame. Especially on a first-gen Camaro! Still waiting on my front caliper brackets....

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I did not edit this post, I hit the edit button instead of the quote button by mistake, so the edit info below shows up.
David

[beadblaster]

I have done this conversion to the 12 bolt in my 64 chevelle. I cut the stock 12 bolt housing ends of and replaced them with the larger style bolt pattern. Housing ends are available from moser for under 100 dollars. I had moser make me a set of axles and bolted the corvette parts on. simple swap. For the front I made my own brakets and bolted on the corvette calipers.

[BRIAN]

There has been discussions on Team Camaro and the front is on D Pozzi web site. If anybody would know it would be him. He is on here regularly.


Vette Brakes used to sell a kit but I think they stopped selling Camaro stuff.

The hurdle was the brake shields and if I remember someone even spoke to Guldstrand about swap.

[Donovan]

All factory JL-8 rear ends used the larger passenger car housing ends and the larger bearing size. I am doing mine this way also. Like I said, I'm doing my conversion as per factory. I got my 12 bolt back and did some mock-ups at my local rearend shop. The shop did a good jod in the conversion, but it was expensive and not perfect. I will need to run spacers to get the rear caliper alignment correct. I don't know why more people aren't doing this conversion, or why nobody really seems to know much about what's involved. I think the later model floating PBR calipers are cheap and lame. Especially on a first-gen Camaro! Still waiting on my front caliper brackets....

how's that swap coming?

[David Pozzi]

All factory JL-8 rear ends used the larger passenger car housing ends and the larger bearing size. I am doing mine this way also. Like I said, I'm doing my conversion as per factory. I got my 12 bolt back and did some mock-ups at my local rearend shop. The shop did a good jod in the conversion, but it was expensive and not perfect. I will need to run spacers to get the rear caliper alignment correct. I don't know why more people aren't doing this conversion, or why nobody really seems to know much about what's involved. I think the later model floating PBR calipers are cheap and lame. Especially on a first-gen Camaro! Still waiting on my front caliper brackets....

A good friend purchased a bare JL8 housing back when they were still available, and swapped his old 12 bolt parts into it, including stock drum brake axle bearings. He still has this car and rear axle.

The reference to large bearings in GM's pamphlet for racing refers to converting a big car rear axle to use in a 1970 Camaro for Trans-Am racing. The text refers to the large bearing and the axle length being longer.

I'm not sure what diameter axles came on production JL8 Camaros. The text lists #3945184 "with rear wheel disc brakes", and another number for drum brakes. The drum axles were special shot peened for racing type.

There were larger dia axles listed in the pamphlet in addition to large bearings from another source I have, but I believe they were over the counter parts for the 1970 season, and not used in the production 69 JL8 axles. Wayne Guinn would know more about the JL8 option. He does mention the larger dia shafts here: http://www.camaro-untoldsecrets.com/...article_fs.htm
David

[676869addict]

try jl8brakes.com this can has a vast of knowledge

[jr421]

I have a complete setup for a 69 that is complete with a rear axel and everything. I am trying to sell it PM me if you are interested