1966 C20 8 lug disc swap

[Cuttyman9]

Can someone direct me to a thread with info and a parts list for an 8 lug disc brake swap.
Mine is a 1966 3/4 ton 2wd long bed fleet side.

Also links to where to get a 4 speed rebuild kit would also be helpful.

I figure I would need a late 70's donor truck, but I'd like to know what years specifically and what is nessisary(spindles, rotors, calipers, master cylinder, possibly upper or lower A arm)

Thanks in advance.
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[1963c-10]

Performanece online has an 8lug conversion kit. I believe its around $1100. Id check them out. For the trans...Im guessing you have the SM-420 Muncie? Are you wanting to rebuild the entire unit or just fix parts of it. I know that Obsolete Chevy Parts has most of the individual components, but I dont personally know of any 4sp rebuild kits.

[Cuttyman9]

Oh I should have been more specific, I was hoping to pull the brake parts from the junkyard, I got the truck for free so it would be counter productive to dump 1100 into just the brakes.
That is what I believe it is, the SM420. I'd like to get gaskets/seals to freshen it up a bit and it crunches with any downshift into 2nd gear, so I would assume it's a synchro.
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[padresag]

Originally Posted by Cuttyman9

Oh I should have been more specific, I was hoping to pull the brake parts from the junkyard, I got the truck for free so it would be counter productive to dump 1100 into just the brakes.
That is what I believe it is, the SM420. I'd like to get gaskets/seals to freshen it up a bit and it crunches with any downshift into 2nd gear, so I would assume it's a synchro.
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there is a lot of info in this section for you. read it. sometimes you can help yourself
. because you sometimes get something for nothing, sometimes doesn't mean that you can fix it for nothing.
you should be able to find a brg and seal kit still for that trans. inquire at any bearing house- places that specialize in bearings
ron

[Cuttyman9]

Oh I realize that, but I like the idea of diggin thought the junkyard much more.
Not to mention, I have brakes already and have 3 other projects so money isn't always available.
But I will dig around on here, I was hoping that someone had a link to a specific thread or website with some sort of walkthrough.
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[Cuttyman9]

Sorry thought the last post didn't work lol

[padresag]

Originally Posted by Cuttyman9

Oh I realize that, but I like the idea of diggin thought the junkyard much more.
Not to mention, I have brakes already and have 3 other projects so money isn't always available.
But I will dig around on here, I was hoping that someone had a link to a specific thread or website with some sort of walkthrough.
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there are links in there are conversions. i know, you don't want to spend the time to look.
ron

[Cuttyman9]

Sorry, thought it would have been a little more straight forward to just ask if anyone knew of them.
I'll go look myself.
Thanks.
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[LostMy65]

Have you looked at the FAQ thread?
FAQ means Frequently Asked Questions.
It's a Sticky so it's easy to find.
It points you to threads on topics that are asked often.
You have several cheap options.
I suggest you do it the way I did.
Read my 66 Service Truck Build thread that is linked in my Signature.
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[Cuttyman9]

I did know what the acronym FAQ stood for, I attempted looking through a part of that I believe but it wasn't all that easy to look through and it was based on a search on yahoo.
I joined to see if I could just ask, and the end half of your statement is exactly what I was looking to find.
What I found most of were 5 lug disc brake swaps for C10's when I looked before registering which is why I shot for asking.


Thank you for all your input, I'll quit bothering y'all.
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[LostMy65]

I do not believe I gave you any flack for asking.
I apologize if there was any tone.
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[Cuttyman9]

It wasn't you, it was the other gentleman.
I'm digging through your other thread as we speak.
Thanks for guiding me to what I needed.
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[LostMy65]

I'm mobile but I think there's links in my thread to threads that helped me.
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[BAMO]

Regarding the transmission, these guys have some rebuild kits - http://www.novak-adapt.com/index.htm. However, you mention the crunching into downshift to second gear. I'm not an expert, but I do believe that second gear is effectively first gear on these trucks (first gear is a granny gear), which would mean, that downshifting to second is probably not something you want to do - kind of like downshifting into first. Now if you are talking downshifting between 4th and 3rd, that's a different story, maybe, but even then gearing is so low you need to go pretty slow to downshift into second. Not saying anything by this, just something I puzzled on for a bit when I started driving mine at first as it took some getting used to. All of this of course is based on my experience with my relatively newly acquired truck, so I could be completely wrong and my tranny may be all messsed up and I am just blissfully unaware (and please no one enlighten me as I am perfectly happy with the current state of affairs).

As for the brakes, unless you absolutely need to switch or you know you can get the parts for a song and know exactly what you need, I'd just get the kit or wait til you can save the cash for the kit. I went down a similar thought process and in the end just swapped out my master to a dual for now.

[Cuttyman9]

Yeah, that is a thought, I usually did that because the brakes are the equivalent of throwing out a block of cheese as an anchor, usually from experience with other cars downshifting with wide ratio style gear spreads usually doesn't necessarily cause that crunch which is why I was quick to assume synchro, but I could be wrong as well.
I would still like to freshen it up.

As for the brakes, I think I'd never buy that kit. It's just not me to buy a kit.
Sure I had to scrounge for it, but I would very much rather dig it up myself than pay someone 1100 for nothing more than research and brand new parts.
Sure if there were something custom like 6 piston calipers and huge rotors that i can't find in the junkyard or whatever then 1100 is reasonable. It's just not my nature to buy a kit.
It's like a crate motor, no elbow grease, no personality.
I appreciate the input.
I'll check out that website.
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[Captainfab]

Upgrading the brakes on a C20 is basically the same as on a C10. You will need the suspension and braking system from a '73-'87 C20. One thing to be aware of is that the '63-'66 C20 lower control are shaft is flat instead of round like the newer years. So switching control arms is not very easy. I do believe the disc brake ball joints should fit the '63-'66 lower control arms. I have not verified that myself though. If you decide to upgrade the rear differential to the very common 14 bolt, I offer the trailing arm mounts that make that part easy.

As for the transmission, have you checked with any local auto parts suppliers? I have not rebuilt a SM420 as those are a dime a dozen around here.

[Cuttyman9]

Oh okay so basically I can take the upper A arm an spindle, swap ball joints on the bottom to the later ones and it should be golden.

Most likely I'll keep the eaton, I like em cuz from what I understand they are 150lbs lighter than the 14, and are equally as strong if not stronger(info that I drew from the 4x4 guys)
If I ever do change my mind, I'll come looking for those mounts.
Actually the Novak website offers a rebuild kit. 218 is pretty reasonable.
The problem I would have in swapping it is if I change to a different trans, it snow balls into going 4x4 lol
Why upgrade and not do what you want lol

Thanks for the input!
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[ozzyman]

The issue with the eaton is gear choices and locker choices. I have a 4.57 eaton and wanted 3.73 gears, not possible so I'm swapping to a 14 bolt which are very strong and have a wide array of lockers and gear choices, also extremely easy to work on.

[Cuttyman9]

Yeah that's what I found as well, but I think if I get to the point of wanting freeway time I'll go for an overdrive transmission, for now with this being a cool farm truck the 4.56's work perfect with my 315/75/16 rear tires and the LSD in the eaton is super strong still(chirps the tires when turning slowly)
The 14 certainly has a strong aftermarket, but I just like the eaton. The swappable third member is cool and bullet proof.

I'll have to post pics, I mounted the mirror and hood emblem, haven't started on the spotlight, and the stacks are almost there.
I'm still amazed the 35" equivalent BFG's fit
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[Cuttyman9]

Oh last question, how simply can you swap disc brakes onto the eaton?
I would assume a 14 bolt discs would fit
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[Captainfab]

I have heard that the rear disc brackets for a 14 bolt will work on an Eaton HO52. Although Ruff Stuff Specialties lists the two separatley. You might ask them to see for sure. Can't beat the price of their rear disc brackets. You still use the K20 front rotors and calipers just as you would on a 14 bolt.

Originally Posted by Cuttyman9

Oh last question, how simply can you swap disc brakes onto the eaton?
I would assume a 14 bolt discs would fit
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On the front discs, you don't have to change the upper control arm. Just change the upper and lower ball joints, and bolt the spindle on.

[Cuttyman9]

I found a website that sells beakers that says I can use a cadillac caliper that allows the use of a mechanical E brake.
Ah sweet, I'll either nab the brakes out of the junkyard or from that guy on CL, seems like a flake.
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[Dusty457]

I am doing the same swap and using everything from a 80 gmc 3/4 ton doing crossmember swap and going to use the leaf spring rear also so far pretty simple and cheap

[Chevy Fleetside]

see if this will help you at all.. http://67-72chevytrucks.com/vboard/s...d.php?t=357610 He used front suspension from an 89 burb. YOu can't use one from an 89 truck. 73 up to 87 would be it.

[Cuttyman9]

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