I bought the brackets (which, btw, are a work of art) from the guy in Canada and proceeded to install the ZO6 calipers. Everything is almost together, so I started checking on a MC. The guy in Canada originally recommended an MC from a 1988 S10. Now he's recommending an MC from a 1972 Corvette.

I did some checking on gmpartsdirect.com and the p/n for the 1972 Corvette mc and the 1969 Chevelle mc are the same.

Either I got incredibly lucky, or there is a problem. Anybody know? What about a prop valve? (No, I haven't been able to drive it yet to answer this question.)

(BTW, I did do a search first).

Thanks.

Is this for a '69? The '69 Chevelle MC was the same for '68-'72 Corvettes.

Oh man...if I'm thinking of the same place that you bought the brackets I wouldn't run those on my car. His bracket has a step in them that doesn't have a generous fillet thus creating a stress concentration there. Guess where the part is going to fail? You guess it.

I could write a thesis on this, but will keep the ol' mouth shut for Al's sake. Just my opinion.

Anyways, back to your question.

First off you have to know if you have a long or short pushrod in your booster. That is if you are even running power assist.

**Note**
If not, then I would suggest you look into some form of it as these calipers have a small (very small) piston area when compared to your old iron moraine calipers you are replacing.

What does this mean? A lot actually. If you go through the calcs for hydraulic pressure needed you'll quickly realize that you need a smaller bore diameter MC when you are going to a smaller caliper piston area (total).

You can go too small though on the MC bore and not be able to "push" enough fluid volume to fill the caliper bores. Thus, its critical to find the proper bore size to fit the bill.

Now, the guy from Canada told you to run the S10 MC because it features a 15/16" MC bore and SAE inverted flare seats facing away from the motor. I hope he told you that the front MC outlet is for the rear brakes and the rear MC outlet is for the front brakes. This is generally opposite of what our traditional GM musclecars ran.

You'll also need to note that this MC is a quick take up design. You can see more info on the quick take up MC on my webpage as I could type my fingers to death about it. Just realize that it requires a special bleeding procedure to get a hard pedal on because of its check valve design.

Also note that this MC needs some mods to fit inside our Moraine boosters (the MC O.D. needs to be turned down on a lathe to fit inside the booster...watchout for that piston c-clip when you turn this MC!!).

Also also note that this MC is to be used when you have a "short" pushrod.

When you have a "long" pushrod you'll need to source out a MC with a deep pushrod hole. Mid '70's 'vettes use these but they have a 1" MC bore (which can be considered adequate), but you might want to try the 18M500 AC-Delco MC with a 15/16" MC bore and cast iron construction. This MC has a deep pushrod hole and the smaller bore will up your line pressure thus making that leg workout less tiring on you.

Hope this gave you some direction to go on. If you have anymore questions please feel free to contact me.

Joe

Thanks, guys, for responding.

Larry -

Yes, it is a 1969 and you are correct, the part number for my 1969 MC is the same as the Corvette. Is this a good thing?

Joe,

This is one of those times when you sit back and ask, "What have I gotten myself into now." Alrighty, then.

Since Joe brought it up, I do have a few issues with that guy up in Canada. His instructions recommend two different kinds of wheel studs (metric and standard). I picked up the wrong kind (metric) and had to go back and get the correct ones.

His instructions recommend an M14-2x40mm screw (which are big honking things) for the calipers. The 40mm are too long, I needed 30mm.

Last, I called the guy several times because of the foregoing issues. He doesn't bother to call me back any more.

Okey dokey. Joe, do you have any recommendations, besides removing the part? Do I inspect it on a regular basis for incipient failure? Kick myself a couple of times?

Thanks, guys!

My advise would to be buy some brackets from Joe-his are way strong enough. I'd hate to drive around wondering if today was the day that bracket would fail when I needed to panic stop.

Is that the Joe, as in 72SSABody?

yep

I don't sell brackets for this particular swap. I'm just making sure people know what is going on & playing devil's advocate.

Serious questions have been raised on other sights (from others as well) on these designs. You can't just sit back and make something of this nature just because you have a 3D CAD system. Heck, I even offered the guy to do some calculations and even went as far as making some suggestions for free just to make sure he doesn't have a customer come back and bite. He wouldn't respond :(

Joe

I'm sorry Joe, I thought I had seen some brackets on ebay that you had designed-my bad. There is somebody on ebay selling brackets that look better than the stepped brackets-maybe email the guy and ask about design and construction.