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Discussion Starter · #21 ·
Disc Brakes were an option in '69, maybe even standard on some models. The '69 and '70 had the same 1-Piston Caliper Brakes. You may want to try to find an original set.
Hi Bill, for some reason 1970 (not sure about 1969) is rare. They were a two piece 12" rotor. I cant seem to find them. Also the Disc spindle is different than the drum brake set up. So far all I can locate that will fit is 11" Corvette discs and Wilwood makes an aftermarket set up. I do not even know if there are original reman OE rotors available. If anybody has an interchange manual or a source for the original set up I am all ears. I will get serious on my research after I get the AC and the exhaust installed. If I am stuck with having to go with a not original set up, I will probably do the 4 wheel disc Corvette set up. I figure the slight benefit of the rear disc setup might offset the extra heat that the smaller 11" rotors will generate in the front compared to the OE 12" rotors.
 

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Actually the '70 had more Disc Brakes than the '69 did. GM was working it's way more and more towards Disc and in '71 I believe every Full Size car had them. Both of my '70 parts cars had them and you are correct about being rare as the complete set-up is a bolt-on for '65-'70 Full Size Chevy cars and they sell pretty quick. Right, you need to change the Spindles as well as a Steering Arm, if I remember correctly. But, I'm sure there are still some out there. I believe new Rotors are also available. If not an exact reproduction, you can get them one way or another. If you decide to go all original, it would be worth a thorough search. I just missed out on another '70 parts car and the Discs were one of the parts I was looking forward to. Of course, it is your call but unless you are going to do some road racing, Factory Disc in the Front and Drum Brakes in the rear should be well sufficient.
 

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Discussion Starter · #23 ·
The rear station wagon rear drums and the police package rear drums were the same (they were wider and better). I do not know that any of the 2 piece 1970 Impala front disc's, are available (new or repops). I will keep looking into this, but from the information I already have, so far it looks like I will reluctantly end up using the bolt on Corvette set up. Since cooling might be an issue (since the disc's are smaller 11" vs 12" front rotors), I will also probably end up using drilled and slotted rotors. This continues to concern me a little as I have been led to believe that the 11" Corvette rotors, use the 70 Impala drum brake spindle's and the wheel offset maybe off a little too much and might effect the Alignment Specifications. Probably not so much as I will probably utilize the 15X8 Corvette rally wheels instead of the Factory OE 15X7 Impala rims.
 

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A few of things here:
  • 1969 and 1970 Impala disc brakes are the exactly the same.
  • Rotor size is 11¾"....people commonly say they are 12" rotors. The difference between a 11" rotor & Impala rotor 11¾" is HUGE. Not only bigger diameter, but thicker. And I think they use bigger calipers and brake pads.
  • C3 Corvette rotor size is also 11¾". No Corvette ever had an 11" rotor.
  • 1969-82 C3 Corvette and 1969-70 Impala (disc brake) shared the same spindle.
  • The C3 rotor and hub can be used on the stock 1969-70 Impala brakes. They essentially the same rotor. I personally verified this.
  • 1969-82 C3 Corvette uses a fixed, 4-piston caliper.
  • 1969-70 Impala uses a floating, single piston caliper.
  • The entire front C3 4 piston fixed caliper disc brakes are bolt on to 1961-1970 Impala.
More info:
The final word on 1969-70 Impala rotors
Impala/Corvette disc brake conversion article #1
Impala/Corvette disc brake conversion article #2
 
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Discussion Starter · #26 ·
Hi Big Dog, You are amazing. I am hoping to have the local rod shop (here in Sevierville Tennessee) assist me with (do) my brake upgrade. I would like to consult further with you. I have some additional questions. The first being is there a way to install the single piston caliper on the 69 to 81 C3 set up (basically/hopefully leaving me with the correct OE 1970 Impala brake set up)? I am hoping this is basically like the Hollander interchange manuals the junk yards have available to them. I have zero working knowledge regarding this conversion / swap. I am hoping that from what you are saying this is not anything different than installing the correct 1970 Impala brake parts. Are the Corvette rotors the same "2 piece rotors" I was advised were the OE Impala rotors? Please Email me, doing this upgrade correctly is important to me. I would really appreciate a call I have a temporary VOIP phone number set up so you can call (it is kind of like a magic jack number) (865)518-6756 also [email protected] Thank you, Cliff
 

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Discussion Starter · #28 ·
As much as I like them original, especially in your case, there is absolutely nothing wrong with dual exhaust, even with a 2-Barrel if you were to keep it. Also pretty cool on your choice of radio.
The only real positive performance update I think is the Winters Foundry Aluminum Snowflake LT-1 manifold. It is much lighter than the cast iron manifold and it obviously should flow much better get better MPG, HP and TQ. I think keeping the intake all in the family (factory Chevrolet) instead of aftermarket should maintain the desirability of the car. I am also probably (eventually) going to get the hoses re stamped (they sell the hose stamps) and order the OE tower hose clamps. The car is not in perfect (undriven condition), but, it is in amazing condition, so I owe it to the car to try not to badly molest it. Obviously when I do certain updates it is better to upgrade than to leave original in some cases. Example: when I do the shocks I honestly think new top of the line shocks are better than to get week lower performing original replacement spiral shocks. JMHO.
 
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