Rotor Suggestions (I'm sure I am overthinking this)

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MountainMan73

MountainMan73

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Hey All new to the forum as of yesterday already learned a ton information thank you all! So I'm sure I'm making a mountain out of a mole hill but long story short. 69 Dart that was frame off by my father 20+ years ago before he passed in 2000. The car hasn't been drove much since maybe handful of times. Last time I drove it the brakes did not want to stop the car prob been 6+ years ago. So I'm going through the entire brake system. Took it apart yesterday and it does have the 73+ disc brake conversion. My question is I know the left side rotor was warped it would spin free then grab. Every part on this car is OEM all Chrysler stuff. Calipers, lines, rotors etc. Do I try to retain the OEM stuff or say the heck with it and bring it to the current part era and replace it all. What do you guys think?? Heres the post I made yesterday that has some pictures of the parts. Im still trying to figure out this whole forum thing lol! New Mopar Junky TIA!!!!!
 
halifaxhops said:
I would stay OEM the new metal sucks. Have the rotors resurfaced.
Click to expand...
This is what led me to my overthinking! I'm sure these rotors have been turned before is there a minimum thickness they need to be? That's what I'm currently researching lol. I do know the calipers are gone there's no getting around that there so rusty and gross I'm just not comfortable with them.
 

Welcome, go to mymopar.com There are downloadable free manuals. Get both a service and parts manual. That will give you your spec.
I would change as little as required to get running/driving/stopping. Calipers/rotors are plentiful for bbp. Chk Rock Auto and Summit, you can also call Dr. DIFF.
 
MountainMan73 said:
This is what led me to my overthinking! I'm sure these rotors have been turned before is there a minimum thickness they need to be? That's what I'm currently researching lol. I do know the calipers are gone there's no getting around that there so rusty and gross I'm just not comfortable with them.
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Should be cast into the outside hub if they are Mopar

1757247266817.png
 
MountainMan73 said:
This is what led me to my overthinking! I'm sure these rotors have been turned before is there a minimum thickness they need to be? That's what I'm currently researching lol. I do know the calipers are gone there's no getting around that there so rusty and gross I'm just not comfortable with them.
Click to expand...
I do not know your skill set but they are pretty easy to rebuild if the inside of the piston where the fluid goes is not pitted. Or
@mobileparts prob has nos ones.
 
4spdragtop said:
Welcome, go to mymopar.com There are downloadable free manuals. Get both a service and parts manual. That will give you your spec.
I would change as little as required to get running/driving/stopping. Calipers/rotors are plentiful for bbp. Chk Rock Auto and Summit, you can also call Dr. DIFF.
Click to expand...
Thank you for this!
 
Well update… The right rotor is .92-.93 and the left is anywhere from .97-.95 Stamped on rotor is .94 so looking like I am going to have to replace. Who is the best go to for good quality rotors
 
Look ar ricksmopars store on ebay. If he doesn't have it, he may tell you where you can get them. I know he has calipers, but they are pin type.
 
bendix and raybestos are still available and of reasonable quality. rock auto carries them as will a decent local joint.
 
How are you going to use the car? That is what determines if a brake upgrade is necessary. The 73+ stock brakes are great and handle stopping duties pretty well even for a hopped up street/strip car. Around 450hp and more strip than street I’d look to upgrade. Or if auto cross or road racing is planned
 
TT5.9mag said:
How are you going to use the car? That is what determines if a brake upgrade is necessary. The 73+ stock brakes are great and handle stopping duties pretty well even for a hopped up street/strip car. Around 450hp and more strip than street I’d look to upgrade. Or if auto cross or road racing is planned
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Not looking to really upgrade this is a numbers matching stock car. Has a 318 in it. Just looking to replace the original rotors calipers from the original conversion my father did.
 
MountainMan73 said:
Oh!!!! Theres no telling. When my father did it I was probably only 6-7 years old. I just remember walking into the garage one Sunday afternoon and he was covered in black paint where he had just got finished spraying the frame lol
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there's no "frame" on our cars. they're unitized body construction. front subframe, rear subframe and sheetmetal in the middle.

so when somebody says "frame off" all the pedantry comes out...
 
junkyardhero said:
there's no "frame" on our cars. they're unitized body construction. front subframe, rear subframe and sheetmetal in the middle.

so when somebody says "frame off" all the pedantry comes out...
Click to expand...
You know what you are correct it shows my ignorance. It was a 57 chevy 210 car he was working as well. Now that Im thinking about it he did have the the k member I believe its called and some other suspension parts hanging up. I have a lot to learn!
 
Looking at the pic, the suspension pieces look pretty fresh, you said he re-did the front end, it seems so.
The calipers look rusty, but that's just cosmetics. The 2 things that count are the piston surface and seal.
Whether that caliper sat on a shelf for however many years, or is on the car, it should be fairly fresh.
The rotors can be turned, they appear fresh , find a machine shop to measure and machine as nec. Let them decide.

You got a nice car there, you're a lucky fella, - and you found the right place for help.

Don't be in a hurry to replace perfectly good stuff .

Good luck
 
MountainMan73 said:
Well update… The right rotor is .92-.93 and the left is anywhere from .97-.95 Stamped on rotor is .94 so looking like I am going to have to replace. Who is the best go to for good quality rotors
Click to expand...
I REALLY would not get too excited about min thickness on those girls. They have LOTS of meat and the pistons have lots of travel. You could easily DOUBLE the allowable cut and still be very, very safe. I have turned hundreds, if not thousands of drums and rotors in a previous life, all the way from little Fiats to over the road truck trailers. And I've relined shoes, and trailer brake shoes, and quite a few winch drums and such.

I know. I KNOW. It's the stated thickness. If this was a single width modern rotor, I would not go .001 under the spec

I still have an Ammco drum/ rotor machine. Turning the rotors, now 3 years ago, when I converted the diesel to 4WD
67Dart273

Thread 'The dummy and the diesel.........The Grey Whale'

For those "newer guys," Del has had an entire "school" of whales, or do they come in pods? White Whale I, II, III, "Mini Whale" (Dakota) and now the "Grey Whale" is an 01 Dodge 2500 Cummins TWO wheel drive.

LET'S convert it to FOUR wheel drive!!

So today I drug home "the wrong frame." Shorter WB, it seems to maybe be a 98 or 99, 4WD and was a Cummings. So what's next? gluing the two frames together to make the correct WB? I "may" have the correct frame available down in Potlatch at considerably more money.......I only paid THREE HUNDRED...
  • Like

img_3777-jpg.1716005520


img_3779-jpg.1716005518
 
Last edited:
67Dart273 said:
I REALLY would not get too excited about min thickness on those girls. They have LOTS of meat and the pistons have lots of travel. You could easily DOUBLE the allowable cut and still be very, very safe. I have turned hundreds, if not thousands of drums and rotors in a previous life, all the way from little Fiats to over the road truck trailers. And I've relined shoes, and trailer brake shoes, and quite a few winch drums and such.

I know. I KNOW. It's the stated thickness. If this was a single width modern rotor, I would not go .001 under the spec

I still have an Ammco drum/ rotor machine. Turning the rotors, now 3 years ago, when I converted the diesel to 4WD
67Dart273

Thread 'The dummy and the diesel.........The Grey Whale'

For those "newer guys," Del has had an entire "school" of whales, or do they come in pods? White Whale I, II, III, "Mini Whale" (Dakota) and now the "Grey Whale" is an 01 Dodge 2500 Cummins TWO wheel drive.

LET'S convert it to FOUR wheel drive!!

So today I drug home "the wrong frame." Shorter WB, it seems to maybe be a 98 or 99, 4WD and was a Cummings. So what's next? gluing the two frames together to make the correct WB? I "may" have the correct frame available down in Potlatch at considerably more money.......I only paid THREE HUNDRED...
  • Like

img_3777-jpg.1716005520


img_3779-jpg.1716005518
Click to expand...
TBH I think thats exactly what I am going to do. Theres no way a few thousandths is going to make that big of a difference. I really want to keep the chrysler parts but don't think im going to get lucky with the calipers cause they are pretty nasty t say the least thanks for the input!
 
Inertia said:
Looking at the pic, the suspension pieces look pretty fresh, you said he re-did the front end, it seems so.
The calipers look rusty, but that's just cosmetics. The 2 things that count are the piston surface and seal.
Whether that caliper sat on a shelf for however many years, or is on the car, it should be fairly fresh.
The rotors can be turned, they appear fresh , find a machine shop to measure and machine as nec. Let them decide.

You got a nice car there, you're a lucky fella, - and you found the right place for help.

Don't be in a hurry to replace perfectly good stuff .

Good luck
Click to expand...
Thanks for the advice! You are right along with my line of thinking. The calipers themselves have been gone through before there's some scratches and knicks on the piston and like you said the seals are all but shot.
 
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