Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Alaskan_TA]
#2452406
02/16/18 01:19 AM
02/16/18 01:19 AM
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Alaskan_TA]
#2452587
02/16/18 03:06 PM
02/16/18 03:06 PM
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Joined: Apr 2007
Posts: 2,914 Calgary, Alberta Canada
a12rag
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I will chime in, as I have done the F,M,J body disc swap on my 70 Sport Satellite . . . no issue with the taller (think it is like 1/8"??) spindle. My car has 10,000 miles on it since doing . . . couple things I ran into . . . needed to put a washer on the bottom original bolts (on the nut side), used rear mount calipers (think from 5th ave), so that bleeder screw was in upper position, and stainless steel brake lines from Dr. Diff . . . no issues at all !!! Think I used the larger rotors with the caliper adapter . . . no tire wear issues - the larger spindle issue is supposedly at FULL extension, where the upper ball joint "might" bind or hit ?? . . . I have never had issue (also used tubular upper control arms from Firm Feel) . . . all is talk until you do it in real world . . . just saying . . . Oh, and yes, have 15x7 road wheels (magnum 500's) . . .
Cheers
Mark
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: a12rag]
#2452597
02/16/18 03:33 PM
02/16/18 03:33 PM
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Joined: Feb 2003
Posts: 7,979 Scranton, PA
Montclaire
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I will chime in, as I have done the F,M,J body disc swap on my 70 Sport Satellite . . . no issue with the taller (think it is like 1/8"??) spindle. My car has 10,000 miles on it since doing . . . couple things I ran into . . . needed to put a washer on the bottom original bolts (on the nut side), used rear mount calipers (think from 5th ave), so that bleeder screw was in upper position, and stainless steel brake lines from Dr. Diff . . . no issues at all !!! Think I used the larger rotors with the caliper adapter . . . no tire wear issues - the larger spindle issue is supposedly at FULL extension, where the upper ball joint "might" bind or hit ?? . . . I have never had issue (also used tubular upper control arms from Firm Feel) . . . all is talk until you do it in real world . . . just saying . . . Oh, and yes, have 15x7 road wheels (magnum 500's) . . .
Cheers
Mark You have a lot of other variables going on there than just spindles. There is also the difference between what is passable and what is ideal. The right spindles are not that hard to find. Keep in mind that Chrysler produced BOTH types concurrently for several years. If they felt it was apples/apples or at least of marginal difference they would have superseded to the taller spindle across the A/B/E platform. If you are going with tubular arms and other non-OE pieces then it probably doesn't matter. Those parts will most likely provide the adjustment necessary to get things back into spec, which you can more easily accomplish by simply using the right spindles to begin with.
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Alaskan_TA]
#2452644
02/16/18 05:15 PM
02/16/18 05:15 PM
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Montclaire
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It's a compromise. If you're fine with that, when the proper parts are readily available, then that's up to you. I have to think that the Chrysler engineer department had a slightly bigger budget than BigBlockDart.com. Their testing, BTW, is full of caveats - baseline settings different from factory specs, and comments like, "how often is your suspension fully extended on main street?," things that tell me we are getting a little off the beaten path. If you are the type who insists on aligning a car in your own garage, then I'd be less worried. Personally, I'd like to be able to go into most any shop from Anchorage to Albuquerque and not worry about having to give a dissertation on my custom needs. We all don't have race/rally cars.
There is a reason why car companies perform extensive testing, both in the lab and on the road, to find the bugs that one or two static tests will not show. And yet billion dollar, multi-national companies still find flaws once the product has been tested to a level they believe is beyond doubt and is out the door. Can you probably rack up tens of thousands of miles without worry? Maybe. But it's not like we are putting juice brakes on a model A - the proper OE parts ARE out there, and available. We aren't talking about a whole lot more effort to do it right.
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Alaskan_TA]
#2452659
02/16/18 05:45 PM
02/16/18 05:45 PM
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Joined: Apr 2007
Posts: 2,914 Calgary, Alberta Canada
a12rag
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The FMJ spindles are not an issue - they are a factory built part. They have been tested by Ma Mopar. The spindles are not going to disintegrate or come apart, and the issue on alignment - no issue. I took my car to the shop and did not mention a thing, they lined it up and it tracks perfect and is not wearing tires, steers and brakes like it should.
Why should it matter if "you align it yourself" in your garage, versus paying for a shop to do the same thing ???
Is that like saying that those that "restore a car themselves" are not as good as paying HUGE $$$$ to a shop to restore the car . . . I know some great mechanics that I would not say are "backyard", they could work in any shop they wanted.
If the after market builds parts, they are tested too - otherwise the lawyers will be on their heels quicker than you can say boo !
What you have to watch using the FMJ spindle, is using the correct caliper that has the bleeder screw at the top, and getting a correct brake line that can be routed correctly and not kink through out the movement. As mentioned, Dr. Diff has stainless steel line that works perfect.
The write up on BB Dart states everything perfectly . . . no issue to worry about . . . the spindles are factory, the alignment specs are factory, the brake calipers/rotors are factory. The hoses, well, they are after market which is actual UPGRADE from factory ! . . . actually, the spindles HELP with some of the alignment issues that happen to the cars over the years.
If you ONLY USE NOS/FACTORY parts for your car, because they are FACTORY and won't look at "aftermarket" parts, you sure have more $$$ to spend on your car than I do . . .
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: a12rag]
#2452670
02/16/18 05:58 PM
02/16/18 05:58 PM
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Posts: 7,979 Scranton, PA
Montclaire
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The FMJ spindles are not an issue - they are a factory built part. Yep, for a different platform. They have been tested by Ma Mopar. Yep, and they are intentionally different for a reason because "Ma" knew they needed to be. The spindles are not going to disintegrate or come apart, and the issue on alignment - no issue. I took my car to the shop and did not mention a thing, they lined it up and it tracks perfect and is not wearing tires, steers and brakes like it should. Yes, because the extremely limited static measurements from an alignment rack will guarantee your setup as fool proof, and are identical to the care and cubic dollars that were engineered in by Chrysler Co. Why should it matter if "you align it yourself" in your garage, versus paying for a shop to do the same thing ??? Is that like saying that those that "restore a car themselves" are not as good as paying HUGE $$$$ to a shop to restore the car You are missing the point entirely. We have members who actually race their cars. These cars are well beyond factory tolerances, and come complete with custom parts set at custom specs. They will have caster/camber settings that a street car will not, but more importantly these people will know their vehicle a heck of a lot better than the average enthusiast who simply wants cheap disc brakes. Not everyone has the knowledge base, and those who do should not recommend changes that would ordinarily be part of a larger picture. If you ONLY USE NOS/FACTORY parts for your car, because they are FACTORY and won't look at "aftermarket" parts, you sure have more $$$ to spend on your car than I do . . .
I have no issue with aftermarket parts. But then again that's not what we are talking about. What we ARE talking about is needlessly using an incorrect factory part.
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Alaskan_TA]
#2452675
02/16/18 06:05 PM
02/16/18 06:05 PM
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Montclaire
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1980 F-body power disc brakes on a 1970 manual drum B-body chassis. What swaps over & what if any additional parts would be needed to convert them?
15" wheel car.
Thanks! Let's start over. Do you want to buy things like tubular upper arms to compensate for a taller spindle? Do you know what your custom alignment specs should be for the best result? Can you explain them to an alignment tech, and know what might result if he/she can't get the car into spec? Do you plan to race the car, or will it be mostly used on the street? Will anyone other than you drive the car (spouse, children, etc.), and are you comfortable with them having to operate a car with a custom suspension setup? Do you put websites like bigblockdart.com on par with Chrysler Engineering? Your answers will guide your decision.
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: a12rag]
#2452730
02/16/18 07:29 PM
02/16/18 07:29 PM
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I am saying it is REAL WORLD experience on MY END talking . . . I got no dog is this fight, but could that statement be equated to the following? "I never worn a seat belt for the last 20yrs and never got hurt, so not wearing your seat belt is competelty safe"?
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Alaskan_TA]
#2452735
02/16/18 07:36 PM
02/16/18 07:36 PM
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Joined: Jan 2003
Posts: 29,648 Hamtramck, PA
Alaskan_TA
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Fluffy Balladeer
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Hey guys, I appreciate all the helpful responses. No need to argue though. Car will not be raced, just street driven. I am not a fan of tubular arms, I have seen more photos of those broken than factory arms, so we can leave custom parts out of the discussion as far as this car is concerned. I also wear my seat belts. Thanks!
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Montclaire]
#2452767
02/16/18 08:31 PM
02/16/18 08:31 PM
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Posts: 25,618 Rio Linda, CA
John_Kunkel
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If you want the car to operate exactly the same but with unicast discs, then you need the 73-76 A-body or 73-74 E-body spindle, which is exactly the same height as what you have now. And you keep saying they're readily available...maybe in your neighborhood, not mine.
The INTERNET, the MISinformation superhighway
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Alaskan_TA]
#2452777
02/16/18 09:05 PM
02/16/18 09:05 PM
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Joined: Jan 2003
Posts: 2,094 central texas
krautrock
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The car has 10" manual drums now.
A pal is selling a rusty 1980 F-body, but the brakes still work, so......
That is why I am asking.
I have already agreed to buy it, but the final price is flexible depending on what all I can use. you can use the spindles, just do the research so you get the right calipers and hoses (or just order them from doctor diff). if your car has a factory sway bar then you want to mount the calipers to the rear, no sway bar or aftermarket, then you can front mount the calipers (swapping the spindles on each side) and the brake hose routing will be cleaner... if the calipers on the donor car are good, you can just use all that stuff and mount the calipers on the rear like factory. i would buy some firm feel upper control arms though so you can run more modern alignment specs since we aren't all driving on bias ply tires anymore like the cars were originally spec'd for...
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Alaskan_TA]
#2452806
02/16/18 09:54 PM
02/16/18 09:54 PM
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Joined: Feb 2015
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crackedback
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Go with the FMJ stuff, it will work fine. I've done a bunch of cars with both A and FMJ stuff, none drove as through they were going to toss you off the road from bump steer. One had about 50K miles on an FMJ swap when I sold it. The scare mongers still exist from the article written in the 90's where IIRC, the author has said he'd never heard of a ball joint failure directly related to the additional spindle height. A friend ran the numbers and the additional angle at ball joint was 1.5* at both ends IIRC, 3* total through the swing. I'm pretty sure the ball joint tolerances were not built where an additional 1.5* was going to jam a stud to housing. This garbage is like a scary movie that isn't so scary...
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Alaskan_TA]
#2452853
02/16/18 11:47 PM
02/16/18 11:47 PM
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Alaskan_TA
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Got it. Thanks again all. I have an appointment to see the brakes in person in the morning.
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Montclaire]
#2453013
02/17/18 01:06 PM
02/17/18 01:06 PM
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TC@HP2
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1980 F-body power disc brakes on a 1970 manual drum B-body chassis. What swaps over & what if any additional parts would be needed to convert them?
15" wheel car.
Thanks! You need everything in between the ball joints. Someone correct me if I'm wrong but I believe if you want to use 11.75 rotors you need B-body Cordoba caliper adapters too. These are available repopped from Dr Diff and others.
Kevin True, but the 10.5 F body units are not too shabby for a cruiser. The F-body spindles are not the correct height. They are taller and will skew the suspension geometry. You want 73-76 A-body or 73/74 E-body. Uhhh, how long have you been on moparts? This topic has been beat to death on here every few years since the mid 1990s from every angle possible. Significant research has been done into it and for all intent, it is a non-issue for all but a few small minority.
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Alaskan_TA]
#2453446
02/18/18 01:34 PM
02/18/18 01:34 PM
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Joined: Sep 2003
Posts: 19,237 north of coder
moparx
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one thing you may run into using the F-body booster is, it might be too big in diameter causing interference with ????. you may also have to modify the firewall hole and the booster mounting holes. with that said, i used a diplomat booster when i switched over to discs on my 64 belvedere. i believe it is real close to the diameter of the F-body. i had to enlarge the rod through hole, and drill two extra holes in the firewall to mount the booster. there wasn't anything in the way to cause interference, as this was a low option car. just some things to consider. and yes, i used the taller spindles with no issues what so ever. if anyone would read up on roll couple and handling issues, the taller spindles would be the ones they would only consider. remember, ALL factory suspension systems [with only a few exceptions such as sporty, handling types] are a COMPROMISE so the masses can "drive" the car without getting into trouble. the factory engineers spend big bucks on design as has been stated, but for "joe average" ONLY, not for hot rod or sports car guys like us. this does not in any way reflect on the latest stuff out there today, only the stuff available "back in the day".
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Re: 1980 F-body disc brakes on a 1970 B-body. What swaps over?
[Re: Alaskan_TA]
#2457938
02/26/18 04:50 PM
02/26/18 04:50 PM
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Joined: Jan 2003
Posts: 512 Niwot, CO Formerly denn...
dynorad
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I did this swap about 15 years ago on a 67 Satellite. The only effect of the taller spindle is a little more camber gain as the suspension compresses. The brake hose wants to be on the opposite side of the spindle so I fabbed up a bracket in the correct new location (such that the brake hose passes through the spindle pivot axis) and made a short section of hard line to connect from the new bracket to the old. Worked great.
Last edited by dynorad; 02/26/18 04:52 PM.
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