Slant Six Forum :: 4 disc swap info

Basically the way I'm thinking is this. I can't convert to front discs without switching to LBP (or, rather, I could, but it would seem to be slightly pointless). If I switch to LBP in the front, I'll want to switch it to the same in back. If I'm going to be swapping the rear end anyway..

With the way 4 wheel discs are becoming more and more common, it's probably going to be easier to find disc parts than drum parts on down the line.

If I switch to LBP in the front, I'll want to switch it to the same in back. If I'm going to be swapping the rear end anyway..

If you have a daily driver , stock motor , city commuter ...it dont matter. If you have heat marks on rotors or live in the mountains its well worth it. I have both.

Be careful, you may be veering into feature-creep territory.

Quote:

Be careful, you may be veering into feature-creep territory.

I have to agree with Dan on this one. I've been down the same path with my Dart, and it's still not back together 2 years later! I wish I just kept it on the road and made small improvements at a time. ... It will be on the road before gasoline-powered vehicles are outlawed...hopefully!

The Ford 8" is the most "bolt-in" axle you can get for your A-body, even more so than a 8.25" Chrysler, which requires driveshaft shortening.

Author:	stephaniebrite77 [ Tue Mar 25, 2008 8:59 pm ]
Post subject:	4 disc swap info
I know the drum to disc conversion topic has been beat to death and then 6 feet under (I waded through 8 pages of threads from the Search function) however my main questions still remains unanswered (unless I totally missed something). I currently have stock 9" drum brakes on my '65 Dart. When I do my conversion, I'd like to convert all at once to 4 wheel disc brakes. I know I could get away with doing front disc/rear drum, but I have a feeling I'm only temporarily paused on beefing up the engine, so I feel having the 4 wheel discs would be a good choice - a bit of extra safety if I keep the engine the way it is, and preventing a second swap if I get crazy to the point where disc brakes become a rather good idea. I have plenty of information on swapping out the front brakes to disc, 74+ A-Body parts, et al (since I'd be switching to LBP I can't use the Scarebird conversion). I found one post mentioning a rear disc swap using some Jeep parts, but that was only if the rear was already LBP and the resulting wheel size is a bit larger than I'm going for. (I'd like to stay at 15" rims max, but probably 14", have no idea about width, don't know that much about wheels yet). So, does anybody know of a way to switch from 9" rear drums to discs without swapping the rear end, or will I have to do a disc conversion and rear end swap together to get 4 wheel discs? Keep in mind I'd like to keep manual brakes if at all possible, and would also like to have some sort of e-brake. Figure since the engine is all but done for now, I might as well start planning for the next big project, if I get plans down now then I can keep my eyes peeled for parts. I'd like to do the brakes next, but if that's not possible without other modifications first, maybe I'll just work on swapping over to a manual tranny.. Oh, and one last question. I saw a post mentioning swapping from the 1 pot MC to a late 60's Corvette MC? And I remember another post mentioning the dual cyl MC's that were available to swap over to, including one that bolted right in.. but for the life of me I couldn't find the post. Can someone refresh my memory on that? Thanks!!!

Author:	Joshie225 [ Tue Mar 25, 2008 9:24 pm ]
Post subject:
I'm here to encourage you to try just the front disc brakes first. I'd be happy to bring my '67 Valiant with stock late A body discs down so you can drive it. I owe DI and Ceej a visit anyhow. My car uses brakes from a '75 Duster and an E body manual master cylinder which bolts right in. The rear brakes are 10x2.5" with the smaller Dakota wheel cylinders to prevent rear wheel lockup. This is plenty of braking power for just about any use you can imagine until you hit the race track. Even then I did pretty well by going with 11.75" rotors and Raybestos Super Stop pads. If you get crazy with the engine and a manual trans you'll probably want to replace the rear end for strength reasons and can better justify rear disc brakes then, but I wouldn't rush. The Jeep rear discs, if they fit the 8 1/4, might fit a big bolt pattern 7 1/4, but even that requires a rear end swap.

Author:	dank10fenny [ Tue Mar 25, 2008 9:38 pm ]
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Unless your gonna be getting into some racing I would just start wit the front discs. Disc-drum compared to disc-disc really isn't much different if you have them proportioned right. Most of the weight goes to the front on braking anyways. You can use the 73+ A-bodies for the disc conversion. I started with the power brakes and hated them so I ripped the booster off. The first problem I had with the switch was having the LBP rims up front and still having SBP in the back, so I had to get a 7-1/4 axle with the LBP to match so I didn't have to carry two spares. As far as wheels go I'm going with some American racing Outlaw II's 14x6 rim. I'm not sure if I could even go bigger because the greater backspacing on a 15" rim. The outer tie rod will hit the rim. Get at me if you need more info.

Author:	Joshie225 [ Wed Mar 26, 2008 7:08 am ]
Post subject:
I forgot about wheel and tire choices. I like the 15x7" cop car wheels. The 4 1/4" backspacing is perfect. You can get a 235/60R15 under the back no problem. I ran 225/50R15 up front though 205/60 would fit too. No problem with the tie rod end.

Author:	SlantSixDan [ Wed Mar 26, 2008 7:30 am ]
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Four-wheel disc systems are not necessarily better. It really is a great waste of money, time, and effort to put 4-wheel disc brakes on a car like yours unless you are racing really fast (Bonneville Salt Flats...). A well-configured front disc/rear drum system will serve you better and create a great deal less hassle and expense for you.

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4 disc swap info https://slantsix.org/forum/viewtopic.php?t=28064	Page 1 of 4

Author:	sandy in BC [ Wed Mar 26, 2008 8:23 am ]
Post subject:
I can speak from experience here. I have been enjoying 4 w/discs on my car for the last week or so....no down side. I used a Ford Explorer rear axle (narrowed on one side) 5x4.5 bolt pattern.....wheels fit nicely in the wheel wells. I used a stock 75 Dart manual master cyl with no proportioning valve. The Explorer E brake is a snap to hookup to the A body cables. The whole swap uses easy to get factory parts. The discs are far superior to the 10" drums.....the 9" are crap compared to the 10". Its not a cheap thing to do....but it kills a lot of birds with one stone. My cost all told was about $700. Its easy to spend that and end up with way less.

Author:	stephaniebrite77 [ Wed Mar 26, 2008 10:53 am ]
Post subject:
Basically the way I'm thinking is this. I can't convert to front discs without switching to LBP (or, rather, I could, but it would seem to be slightly pointless). If I switch to LBP in the front, I'll want to switch it to the same in back. If I'm going to be swapping the rear end anyway.. The other thing I was thinking about in regards to this is the fact that I'm planning on keeping my car for a long time, in fact I have no plans to sell it since it's the first car I've ever built up and I'm sentimental like that. With the way 4 wheel discs are becoming more and more common, it's probably going to be easier to find disc parts than drum parts on down the line. I think this is more an issue of preference as I don't particularly see major differences between disc/drum setups and 4 wheel discs as far as drivability (or would that be brakeability?) is concerned. The setup that sandy in BC has sounds about like what I want, and I'm glad it seems like it's working out. Sandy, I hope you don't mind if I occasionally bug you for details. I'll probably save the money up over the course of this coming year and do the brake swap as next year's spring break project. Personally, it makes more sense to me than going with the disc/drum setup, and it doesn't really feel like a waste.

Author:	SlantSixDan [ Wed Mar 26, 2008 11:04 am ]
Post subject:
Quote: Basically the way I'm thinking is this. I can't convert to front discs without switching to LBP (or, rather, I could, but it would seem to be slightly pointless). If I switch to LBP in the front, I'll want to switch it to the same in back. If I'm going to be swapping the rear end anyway.. Be careful, you may be veering into feature-creep territory. Quote: With the way 4 wheel discs are becoming more and more common, it's probably going to be easier to find disc parts than drum parts on down the line. There will effectively never be a problem getting parts for the rear drum brakes.

Author:	DusterIdiot [ Wed Mar 26, 2008 11:15 am ]
Post subject:	We got that stinkin' rear end...
Quote: If I switch to LBP in the front, I'll want to switch it to the same in back. If I'm going to be swapping the rear end anyway.. Unless your engine is putting down some heavy performance the 73-up discs and 10" rear drums will be more than enough stopping power ... On the note of LBP rears, Ceej has a spare 7.25" rear with 10" drums I think, I also have a similar setup in 'the shed' I keep as a just in case LBP emergency swapper... So getting an A-body LBP rear won't be too hard. Rear drums will still be made, but the quality won't be any different than the chinese rotors that are on the market now, if buying new... -D.Idiot

Author:	Dart270 [ Thu Mar 27, 2008 7:16 am ]
Post subject:
I have to say that 4whl discs DO make a substantial difference over disc/drum. If you have a low power car with LBP rear drums, may not be worth it, but... If Stephanie wants to go LBP, it is not much more expensive to set up a disc rear these days than a good set of drums. Putting front discs was one of the best mods I ever did to my '64 Dart, and the rears were also a very good mod. Go for it! Lou

Author:	sandy in BC [ Thu Mar 27, 2008 6:06 pm ]
Post subject:
I agree that if you have a free 10" LBP rear of sufficient capacity for your build...its hard to beat. I dont agree that in any kind of heavy duty braking situation that the 10"brakes are even close to a 4 wheel disc setup. If you have a daily driver , stock motor , city commuter ...it dont matter. If you have heat marks on rotors or live in the mountains its well worth it. I have both. I drove Volvos for years with 4 wheel discs...its hard to go back to dumpy drums that are never well adjusted because of rusted hardware....

Author:	stephaniebrite77 [ Thu Mar 27, 2008 7:00 pm ]
Post subject:
Quote: If you have a daily driver , stock motor , city commuter ...it dont matter. If you have heat marks on rotors or live in the mountains its well worth it. I have both. Until I started going to school I was a pretty avid explorer, I love road trips, and even though I live in the city (if you can call Salem a city) back roads driving is still my favourite - a byproduct growing up between Big Sur and Santa Cruz, California. Also, I do enjoy snowboarding and plan on taking my car to the mountains this coming winter as much as I can now that I can trust my engine to make the trip. I'd also like trust that make brakes can handle whatever comes up. :deep breath: So. I appreciate all the feedback and the opinions, both for and against 4 wheel disc systems. While I understand the reasonings behind the against opinions, and I thank the people who have offered and explain them.. I just don't happen to agree. Purely as a technical discussion, rather than heading into a "my way is better" debate that we'll never agree on... How would one go about converting a '65 Dart with 9" drums to 4 wheel disc brakes? Sandy, I know you used an Explorer rear end. Is there a particular reason why? I found the thread where you posted details about the swap, but when it comes to differentials and gears and all.. I don't know anything. At all. So about half of it sort of glossed over my brain. Dart270, did you go the same route or do something different? Are there other options besides the narrowed rear end from the Explorer? Maybe something that won't need quite so much customization? I don't know yet how comfortable I am with fabrication, and don't know if I'd be able to afford lots of machine shop time. I read something about a Ford Ranger..

Author:	Dart270 [ Thu Mar 27, 2008 7:14 pm ]
Post subject:
Stephanie, OK, the fronts are easy - 11" spindles and upper control arms from a 73-up Abody are the factory parts you need. For the rear, I highly recommend a Ford 8" axle from an early 70s Maverick or '65-66 Mustang. Get the 5 lug unit and they are BBP already. You don't even have to shorten your driveshaft and the width is just right. You can also use a 78-80 Granada 8" axle, but will have to use deeper offset wheels (like 94-04 Mustang). Leaf spring perches are right too. For this, you can get a rear disc kit from tsmmfg.com or other places. Junkyards up near you should have some Mavericks laying around. The Ford 8" is the most "bolt-in" axle you can get for your A-body, even more so than a 8.25" Chrysler, which requires driveshaft shortening. Lou

Author:	Patrick Devlin [ Thu Mar 27, 2008 7:15 pm ]
Post subject:
Quote: Be careful, you may be veering into feature-creep territory. I have to agree with Dan on this one. I've been down the same path with my Dart, and it's still not back together 2 years later! I wish I just kept it on the road and made small improvements at a time. When I lost an axle in the 71/4" rear, in went the 8 3/4" rear with 3.55 SG. When a ball joint went bad, in went the .920" torsion bars and Edelbrock IAS shocks and 16:1 steering. When the voltage regulator died and fried my gauges, I cut the dash to put in "real" gauges. It goes on and on. When the car got rusty, it was time to park it and cut out the bad metal...the car is now in 100 pieces waiting for me to get finished necessary renovations on my house. It will be on the road before gasoline-powered vehicles are outlawed...hopefully!

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