Wanna slam that 63-98 C10/C1500? Lets talk about it!

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bluex

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Yeah, I didn't find out about those shafts until after I'd rebuilt them and I am definitely not doing that again haha. I'm saving up for the QA1 full setup so these just need to last me another couple years.

Granted, it got aligned 23k miles ago when I put the 20s on and hasn't been touched since, so it's definitely possible it got knocked out. Could be toe or camber at this point (or both). IIRC, I told them to put as much caster as they could get in it and keep the camber around 1*. I think it ended up being around 1.5* of camber, which would be fine if I didn't do so much highway driving. All of my Mustangs in the past, I've had them set at 2-2.5* of camber and always had good tire wear, but I always cornered very aggressively, went on lots of mountain runs and generally drove it like I was on a road course. Hardly ever did highway trips though and highway trips are 80% of what I do with this truck.

I do remember they suggested getting the longer studs so they could put more shims in but I didn't want to, that's alot of leverage on there.
I hope you left the - off your camber numbers there. You want negative so it doesn't go so positive during aggressive corning. My dd charger has about -1.7* and while it does wear the inner more its not super bad but it is a completely different suspension setup compared to these trucks. I'd like to get it down closer to -1 but nothing on it is adjustable except Toe

When you install the QA1 stuff try this, you probably know some of this but for the benefit of those who might not, this is how I like to start when everything is fresh an new. With aftermarket arms its a really good idea because they usually have some geometry improvements built into them and starting from scratch is the best way to get it right.

Take a look at the shim stackup as it is now. Usually the rear stud will have more shims than the front. This is how the caster is set. Remove all the shims and count them. They should match up usually except for the last couple. By that I mean if the first one behind the nut is 3/16 then it should be the same on both sides. If, for example you have 4 more shims on the rear than the front then leave those last 4 as your base caster setting, or you can leave 5 if you feel it needed more caster (which it probably does). Don't put any on the front stud and make them start from scratch. This will probably cost more than a toe and go but you're also more likely to get a better alignment IMO. Also while everything is apart, pull the inner fenders out. This will help access for the alignment guy, save him some time which should save you money. If you do this and you set the truck back down and it has a ton of negative camber you can start adding them back, equally to both studs to get it close to where it should be. I think you'll find that it wont need as many shims as you think and if its close to my specs above you'll be more likely to get that as opposed to just a toe check/set and thrown out the door. Even when you ask for your own specs they will still pull up make/model info on the computer. If its close to that spec then they will probably be reluctant to make a change even if that's what your asking for. That's why I said you need a shop that will work with you and will do what you ask. Be prepared to pay more, because your standard alignment for $60-80 is usually a toe and go and they don't want to get into shimming anything because of the time involved. Offer up front to pay the shop hourly rate if necessary or for an alignment and a hour of time etc. Whatever it takes to get what you want it set to.

Alternatively buy one of these an do it yourself and know its done right.

https://quicktrickalignment.com/product/4thgen/

I was nearly to this point and I still might do it. Even though I have a couple of shops who know and will work with me I still have to pay extra or keep and eye on them to get exactly what I want out of the alignment. Modern cars with nonadjustable caster and camber have really hurt us in this as it has conditioned the shops to just not mess with those settings, even if it is adjustable. That's a bad thing because it makes it hard to find someone willing to do the extra work or that even knows how.
 

Terry Wilkerson

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Really good write up.
Thanks.
 

Bennyt

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Great write up. Only things I would add and this is only my opinion and experience (73-87):

I believe AZ Pro Performance spindle you mention is CPP's Modular spindle. CPP manufactures/ sells 3 different spindles. The first is the standard drop spindle similar to all the others out there. 2. Is their Modular spindle. It does not need to be cut for big brakes and uses a drum brake width for better clearance. 3. is the X10 spindle which uses a removable Corvette(?) hub to handle the increased side load of big wheels and low pro tires.

Flip kits, I suggest flip using a new perch welded on and skip all the brackets. Saves money if you can weld.

C-Notch. Not impressed with most that are sold as they weaken the frame. Do not bolt on, only weld. I like the Porterbilt and Built by Brooks that fully encapsulate the frame. For wood floor beds, you'll need to check bed floor clearance with these two and adjust accordingly.

Really like the suggestion of the Flip kit and using a lift shackle if don't want to go low, at first. Might just do that on my C30.

If you have a wood floor bed, drop shackles will probably interfere with the floor as it's 5/8 thick and not 16-18 gauge sheet and not much clearance to work with.
 

TotalyHucked

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I hope you left the - off your camber numbers there. You want negative so it doesn't go so positive during aggressive corning. My dd charger has about -1.7* and while it does wear the inner more its not super bad but it is a completely different suspension setup compared to these trucks. I'd like to get it down closer to -1 but nothing on it is adjustable except Toe

When you install the QA1 stuff try this, you probably know some of this but for the benefit of those who might not, this is how I like to start when everything is fresh an new. With aftermarket arms its a really good idea because they usually have some geometry improvements built into them and starting from scratch is the best way to get it right.

Take a look at the shim stackup as it is now. Usually the rear stud will have more shims than the front. This is how the caster is set. Remove all the shims and count them. They should match up usually except for the last couple. By that I mean if the first one behind the nut is 3/16 then it should be the same on both sides. If, for example you have 4 more shims on the rear than the front then leave those last 4 as your base caster setting, or you can leave 5 if you feel it needed more caster (which it probably does). Don't put any on the front stud and make them start from scratch. This will probably cost more than a toe and go but you're also more likely to get a better alignment IMO. Also while everything is apart, pull the inner fenders out. This will help access for the alignment guy, save him some time which should save you money. If you do this and you set the truck back down and it has a ton of negative camber you can start adding them back, equally to both studs to get it close to where it should be. I think you'll find that it wont need as many shims as you think and if its close to my specs above you'll be more likely to get that as opposed to just a toe check/set and thrown out the door. Even when you ask for your own specs they will still pull up make/model info on the computer. If its close to that spec then they will probably be reluctant to make a change even if that's what your asking for. That's why I said you need a shop that will work with you and will do what you ask. Be prepared to pay more, because your standard alignment for $60-80 is usually a toe and go and they don't want to get into shimming anything because of the time involved. Offer up front to pay the shop hourly rate if necessary or for an alignment and a hour of time etc. Whatever it takes to get what you want it set to.

Alternatively buy one of these an do it yourself and know its done right.

https://quicktrickalignment.com/product/4thgen/

I was nearly to this point and I still might do it. Even though I have a couple of shops who know and will work with me I still have to pay extra or keep and eye on them to get exactly what I want out of the alignment. Modern cars with nonadjustable caster and camber have really hurt us in this as it has conditioned the shops to just not mess with those settings, even if it is adjustable. That's a bad thing because it makes it hard to find someone willing to do the extra work or that even knows how.
Yes, I did leave out the - on my camber numbers, whoops. I completely agree with everything you're saying there. Luckily, I do have a good alignment shop near work that's been there for 50+ years and has a 60+yr old tech working the rack. He smiled real big when I brought my truck in and said "man, I haven't done one of these in a long time. This will be fun". I told him what I was after and had told the guy up front I'd pay extra. They were great to work with.

I do plan to get one of those alignment kits once I have the QA1 kit. I used to work for a race team and did most of our setups before race weekend and adjustments during, so I definitely want to be able to make my own changes as I go and learn what the truck likes rather than having to drop it off and try to communicate that to a non-motorsports person
 

bluex

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Great write up. Only things I would add and this is only my opinion and experience (73-87):

I believe AZ Pro Performance spindle you mention is CPP's Modular spindle. CPP manufactures/ sells 3 different spindles. The first is the standard drop spindle similar to all the others out there. 2. Is their Modular spindle. It does not need to be cut for big brakes and uses a drum brake width for better clearance. 3. is the X10 spindle which uses a removable Corvette(?) hub to handle the increased side load of big wheels and low pro tires.
The React spindle I mentioned is for 88-98. It's a completely new design Travis had done from scratch. It's not available anywhere else an was desperately needed for those trucks. I believe he worked on it in conjunction with Baer for the brake kits he also offers for those trucks. His 63-87 brake kits do utilize the CPP Modular spindle or you can modify a standard one.
 

tobiahr

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I would add that a K5 requires a notch with a axle flip. I had less than 2" clearance from the frame after removing the bump stops.
 

bluex

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I would add that a K5 requires a notch with a axle flip. I had less than 2" clearance from the frame after removing the bump stops.
Same with a 'burb

You guys are correct, thanks for the reminder. Don't deal with those as often so they slip my mind. Added to the main post C notch section
 

ChuckN

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Lowering your C10/C1500 (1963-1998)

So, you want to lower your truck? Got questions about how/why/what to buy? Hopefully this will help with your decisions. I will try to address most of the common questions/issues and give you a good idea of what to look for and anything that will trip you up. I know this is a squarebody forum but most of us have multiple projects and this information transfers across all these years. We will start at the front; I’ll break it into sections and try to go item by item.

FIRST OFF, In my opinion AVOID any and all of the prepackaged kits and all types/kinds of “drop shocks” I’ll explain more but that’s always the first question and will lead you to a compromise that will make you unhappy with some part of the kit or the ride quality.

Spindles:

Always start your drop here. Spindles help keep the factory ride quality, and alignment specs are easier to maintain. While they are slightly more involved on the install and cost more up front, it is the best option for the first part of the drop process.

There are 2 places that cast drop spindles, so regardless of whose name is on them, they pretty much come from the same place. Any of the bigger name companies are fine to purchase from. They all have a good track record, and all the standard spindles have the same clearance and install issues. There isn’t one that is noticeably better than another.

For 63-87 they come in 2.5” or 3”. It doesn’t really matter which one you use. If you want to keep 15” wheels I would do the 2.5” since it won’t require as much trimming to the a-arm. Anything 17” and over on wheel size should not require trimming. You will have to trim in this area for wheel clearance, it does not affect the strength of the arm at all. Leave the bump stop area alone for a static drop, the trimming you'll need to do will be on the edges out by the ball joint on both sides of the A-arm.
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All 63-72 spindles are setup for 1.25” rotors. If you want to build your own disc brake conversion you can get the spindles and then rotors/bearings/brakes for a 73+ (if you want 5 lug) the swap kits are generally about the same price as buying all the stuff on your own though. If you want to stay 6 lug those rotors are available but only for 1.25” spindles. So yes, if you want them on a 73+ they will work with the correct spindles for a 6 lug 2wd.

On 73-87 you can have 1” or 1.25” thick rotors. Generally, 73-80 are more commonly going to have 1.25” and 81+ will be 1”. However, you still need to measure before ordering the spindles because the trucks could have been ordered either way through the model years. From what I’ve seen there’s no rhyme or reason as to why one truck got “big” brakes and one didn’t. So, save yourself the hassle and measure them before you order. You don’t need a caliper to measure them just to know what spindle to use, a tape measure is fine, but measure the same way it shows here.

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Aside from the A-arm trimming the brake line will need bent to clear the spindle ear and the ball joint nut. This is easily done after everything is bolted up, you can take a large crescent wrench and bend it slightly until it has room around everything and while turning. I have also run across a few sets of spindles where the dust shield bolt holes are not tapped deep enough for the factory bolts. Watch that because if they bottom out before the shield is tight and you try to keep going, they will break off in there.

88-98 all C1500 spindles are 2” drop, and you also still have the option of 1” or 1.25” brakes. The 1” rotors are far less common in this generation though. 88-91 regular cabs were the only ones that could get 1” rotors. 92 and up everything was 1.25”. All extended cabs, Tahoe and Suburban are 1.25”

All the spindles for these trucks widen the front track width, except for the React spindle from AZProPerformance. This is a new(er) spindle and should be the go-to unless you’re on a serious budget. Any off the shelf cast wheel with a 245 or wider tire will need the fenders rolled for clearance (4” or more drop) unless you use the React spindle.

The brake line might need some bending here as well but there are no a-arm scrubbing issues on these trucks with 15” wheels. However, while the front end is apart do yourself a favor and remove the knockouts from the upper a-arm. The tool is cheap, but it can be done with a punch and a hammer. If you plan to lower more than 1 truck the tool is a good investment.
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Link to the tool:

There are a lot of other options for spindles now (63-87), I tried to stay just on stock style for this post. I have used a set of the new CPP X10 with the hub less rotors. That’s a nice setup and gets slightly bigger brakes. I haven’t been able to get a set, but I also like the looks of the Detroit Speed kit that utilizes a GMT900 hub, rotor and caliper. I am big believer in easy-to-get factory parts as I like to drive my trucks and I don’t want to be stranded somewhere because of a custom part that has gone bad.
Thanks so much for posting this! I feel that I got my Christmas present! And since you mentioned the clearance issue with 15” and drop spindles, you may have sold me on the CPP items. Great write up!
 

TexasSierra

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Perhaps I missed it, but are any modifications required on 73-80 arms at the bump stop? 2 1/2 spindle and 1 inch spring.
 

LocoLocal

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You get new Delrin bushings, new ball joints, they will eliminate the clearance issues with 15” wheels and offer some geometry improvements over stock arms.

This is exactly the info I came here for. Thanks a bunch for the post.

Now, the question is (thinking out loud): do I spend the money on the control arms, which could use replacing anyways, or do I put that money towards new wheels that would also eliminate the issue? My wheels have seen better days and could use replacing or at least refurbishing, too. But then, I would still want to beef up the stock control arms if I am going with a 5" drop (3" spindle, 2" spring). And, if I get new lower control arms, now I am looking at a new sway bar that uses end links.

Ah, don't you just love how these projects just snowball?

I appreciated the info on the shocks as well. I was wondering if those lower shocks were worth it.

Thanks again.
 

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