Daniel828

I have a 66 cutlass with a 455, still has front drums. I want to do a disc conversion. I scored a arms and spindles from a fifth gen el Camino , a g-body essentially, for 20 bucks off craigs list. Can I use these parts to do a disc swap?
Thanks
Dan

joe_padavano

Not easily.

The ball joint and tie rod ends have a different taper angle on the G-body than they do on the 64-72 cars. While you can physically bolt them together, the tapers do not seat properly. The result is NOT SAFE to drive. Since the tapers are not properly supported in the spindles, the ball joint can eventually fail. That never ends well.

You CAN use these parts, but it requires you to use the G-body ball joints. The uppers can fit in the A-body control arms, though you may need to modify the bolt holes. The lower ball joints require the OD of the ball joint housing to be machined down to fit in the A-body lower control arm. You also need to use the G-body outer tie rod ends, which in turn require special adapter sleeves to mate to the A-body inner tie rod ends. Of course, after doing all this, you end up with the crappy small-bore metric calipers that have less braking force than the A-body calipers (2.375" pistons vs. 2.75"). No, you cannot simply put the older calipers in the G-body spindles. Yes, you can buy aftermarket large bore calipers for the G-body spindles. Expect to pay more for that than for a proper disc brake conversion kit. Oh, and when you've got that all sorted out, you still have the problem of the steering arms being in the wrong place and causing bump steer.

Common sense should tell you that if this were an easy swap, it would be all over the interwebs years ago. Don't F with your brakes and steering like this.

Daniel828

therobski

Have you ever considered the "B-spindle" upgrade? There are posts on the details of this upgrade using GM parts in this Club and on google. It was actually 6 years ago locating the parts and assembling it all on my 64 F-85. In a nutshell, just from memory-located B-spindles took off a 91-92 Buick Roadmaster wagon, new IROC-ILE 13 inch rotors from Rock Auto, Caprice police calipers-forgot the years for these. I took the Caprice Police car caliper part numbers to a good parts house-not Auto Zone etc.and gave them the part numbers of the GM calipers and to be on the look out when they receive all the rebuilt calipers to restock the shelves and let me know and low and behold 2 weeks later I was in heaven. Then used 86-87 Buick GN tie rod ends, F body bearings. Good part about this upgrade I used GM parts, and it took a lot of the under steer out of these early A-Body's. The aftermarket makes kits for this but I like what has turned out and those GM parts will get the job done VS chinessim.

Daniel828

joe_padavano

Typically not. The B-body swap uses 12" rotors, and even then not all 15" wheels are created equally. The only problem with the B-body spindle swap (aside from the cost of the custom shorter upper arms and the fact that you have the same ball joint and tie rod end issues as with the G-body parts) is that you also still have the bump steer problem. You can use tall upper ball joints and get the same handling benefits as with the B-body swap without the hassles and custom parts.

There's also a low-buck way to put 12" Corvette brakes on A-body spindles.

therobski

Thanks Joe, IROC 1LE rotors are 12inch not 13 inch. The F-85 has stock GM big Olds 15x7 rims fit fine. Lot's of options out there now vs. 6-7 years ago when I started my parts search

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joe_padavano

I know that. The OP asked about 13". I responded with this.