What's do I lose???
 

Hey fellas, I have a 77 C20 crew cab that I'm going to make into a crew cab short bed. My biggest concern is that I also want to change the 8 bolt to the more common 5 bolt. Does this cause any issues with towing a 22' car trailer with about 2800lbs inside??? There has to be a good reason that bigger trucks all have more lugs but to what extent would be considered safe? So this means sourcing out a 12 bolt or 10 bolt from a C10 and using the front spindles also. I understand that making it a short bed will hurt the stability a little but this thing is to damn long :waah: so the short bed is already bought and in the plans.

This is what I'll be pulling possibly once a week
http://i755.photobucket.com/albums/x...s/13d55949.jpg
http://i755.photobucket.com/albums/x...s/d2758c43.jpg

Thanks
Slim

Re: What's do I lose???
 

Factory C10 brakes would be stretched to the limit. If I was changing it to just get the 5 lug wheels, I would upgrade the disk to bigger ones, maybe even 4 wheel disk brakes.

Other wise I would keep it as a 3/4 ton model.

Just my $.02

Re: What's do I lose???
 

Oh yes, I'm going with the 14" rotors front and back from the ss camaro 2010. I actually have the front setup I was more worried about the number of lugs (8 to 5)

Re: What's do I lose???
 

If you plan to your it you can still use 3" drop spindles from a C30.

Plus there is now a ton of rims available for 8 lugs.

Before I got my 4x4 one of my plans was to slam my C20 with 20 inch rims.

Re: What's do I lose???
 

I want to bag this bad boy so the big 8 lug wheels are not going to be ideal. I put my buddies 24x12 on it the other day and it sticks outside the fender. I'm really not into the higher trucks and it looks like 8 lugs is perfect for that

Re: What's do I lose???
 

They have different widths, and offsets. That's is before you get custom off set sizes.

Center Line Wheels has plenty of styles.

Re: What's do I lose???
 

Keep your 3/4 ton running gear. It's there for a reason

Re: What's do I lose???
 

Why take vehicle pretty much suited to towing, and convert it to something not suited to towing, and then tow with it?

The OP may want to go to the local parts store and ask to look at front rotors for a 2010 3/4 ton Chevy truck, and Camaro for comparison.

Re: What's do I lose???
 

I appreciate your concern and I'm taking notes from everyone's advice.
But!!!!
Well I don't know about 2010 3/4 ton rotors but the camaro rotors that I have in my garage are a lot larger than what's on here now. I figured these would be an upgrade to say the least. I'm going to lower this thing no matter what I'm just curious as to "what do I lose" going from 8 lugs to 5 lugs. I'm going for a laid out on the frame but I have to tow occasionally.

If someone could explain what the big concern I should have if I had three less lugs....

Thanks slim

Re: What's do I lose???
 

Three less lugs is not the big concern, but what is behind those lugs. 3/4 ton running gear is heavier duty (brakes, axles, differential, and even the housing). If you could convert a full floating 3/4 axle to 5 lugs you MIGHT get the capacity of the original setup, but you still have the lighter duty 5 lug wheels.

My truck (84 C10 350) is the lightest duty full size truck that GM made in that era. The idea seemed to be that a truck that looked and rode more like a car would get gas mileage and emission numbers that would meet EPA standards easier.

I tow a 5000 pound 76 travel trailer with the truck, but wish I had the 3/4 ton running gear. Trailer brakes help, but bigger would be better.

If I was in your position, I would keep the heavy duty running gear and suspension, lower the truck and look for 8 lug wheels to finish the look.

Do not take this as offense, but building a truck from the wheels in is not the best approach. Build it stout enough to do the job from the motor out to the axles and let the wheel/tire combo be your last consideration.

There seems to be a LOT of options for wheels and tires now days, so you shouldn't have a problem finding good looking stout 8 lug wheels.

Re: What's do I lose???
 

there are more lugs on larger trucks for many reasons and not just to look cool or differentiat the rating of a truck. usually on larger trucks you have every thing behind the wheel is larger creating more area to secure on the wheels and do it safely. half tons dont have as many lugs becuase they are not expected to perform the same functions as a heavier duty truck would. Think of it this way. When you have a heavy load on a trailer the heavier the load the better you want to make sure it is secured because of what could happen if it came loose, right?
in todays market there is a rather large market for custom 8 lug wheels considerbly more than there was 20-30 years ago so look at your options and keep the 3/4 running gear under your truck you will be glad you did.

Re: What's do I lose???
 

I feel the diameter of the brake rotors is not as critical thickness when talking about trucks. While the larger rotor will have more surface area it is a trade off because the thinner rotor cannot take the heat load being put into them by stopping a 7000lbs truck when they where designed for a 3800 lbs car. Stopping a big truck with camaro brakes while pulling a trailer is in my mind unsafe and will lead to brake issues you probably have not thought about, like warpage.

I'm a fan of putting one ton brakes on a 3/4 ton, it's not a hard swap, and you will notice an improvement.

Nate

Re: What's do I lose???
 

Ok. Here's what I've found out spec for spec with the differences of the two brakes in question. There's not much of a difference in thickness but the SS brakes are larger in diameter

Camaro SS
http://i755.photobucket.com/albums/x...ps26c5190c.jpg

77 C20
http://i755.photobucket.com/albums/x...ps07ea3cc4.jpg
http://i755.photobucket.com/albums/x...ps7a63d497.jpg

I understand that I'll be using a lighter duty wheel but my entire trailer loaded with the goods is about 5000lbs. As far as the rear goes I actually have a Dana 44 out of a 2008 srt8 jeep Cherokee that I can use. It has the big brembro 14" brakes on it from the factory. I'm thinking that is more heavy duty than a 12 bolt and maybe even pretty close in strength as the stock 14 bolt.....

Re: What's do I lose???
 

IMHO, you would do far more work trying to put in lighter duty axles than buying different offset rims. Plenty of guys have slammed crews with 20"+ 8 lug wheels tucked in the wheel wells. Would a 10 bolt or 12 bolt handle 5000lbs....yes, but I wouldn't want to do it on a regular basis. The heavier running gear is just far more trustworthy for that.

Re: What's do I lose???
 

When you say lighter duty axles are you saying to get a 5 lug pattern axle in the 14 bolt?? To be honest I just don't like the look of 8 lug wheels unless it's on a lifted truck.

Re: What's do I lose???
 

What I meant was to find a set of 8 lug rims with a different offset to clear the wheel wells, but I can see your point on not liking the looks of 8 lug rims. If you are set on wanting 5 lug and plan on pulling with it regularly, then I would advise making sure the axle is beefed up as best a possible. As far as the Dana 44 from the Cherokee, I'm not sure if that will actually fit. It seems like that axle would be too narrow.

Re: What's do I lose???
 

The srt8 rear end measures 67 1/2" outside flange to flange. It's 3:73 gears with the big brakes on it

Re: What's do I lose???
 

Don't let anybody fool you....a Dana 44 is nowhere near as strong as a 14 bolt corp axle.
The main thing you lose is the difference between a full-floating axle and the lighter duty semi-floating axle.
With a full floating axle, even if it where to break, which is far less likely in the first place, the wheel does not come off of the truck.
The 8 lug stuff is there for a reason, don't defeat the safety aspect, nor the gearing needed to tow.
You have the right stuff, just adapt it to look the way you want....

Re: What's do I lose???
 

I see where everyone is coming from. The big deal is the full floater 14 bolt. If it's a must that I keep it do you think there would be a big problem getting some currie or eaton custom axles for a 5 lugs in the 14 bolt??? This is my last resort and I give up :lol:

Re: What's do I lose???
 

91-9x 454SS trucks were 14bolt rears w/HD 5-lug axle pattern so something custom could prob be done. You could find a housing from one of those trucks to swap but they're possibly wider (they are wider than say a 77 12-bolt housing).

Perhaps a phone call to Currie is in order....

That being said, what 5-lug wheels are you planning to run?

Re: What's do I lose???
 

Some really big hoops.
http://i755.photobucket.com/albums/x...ps82d10212.jpg
http://i755.photobucket.com/albums/x...ps228b08dd.jpg

The tires will be larger than what's on there now. I bought these and was going to keep these on the c10 but I ended up giving my friend the c10 with dropmember and all

Re: What's do I lose???
 

http://www.team-bhp.com/forum/attach...c-imag0011.jpg

Ignoring the center configuration, and looking at left and right.

Right-hand image:
Original, 14 bolt 10.5" full floater in your truck.

Left-hand image:
10 bolt
12 bolt
14 bolt w/9.5" ring gear (someone mentioned the 454SS truck, same axle as 81+ light 2500 squares in 8-lug, same axle as GMT-400 heavy half/light 2500 in 6-lug, and GMT-400 light 2500 in 8-lug, vans, lots of apps.)
Dana 44 from Jeep that you're looking at.

Look at the images above, where the loads are carried specifically. In a semi-float they are carried on the end of the axle itself. When I say axle I mean the shaft connecting the side gear in differential to your tire/wheel. In the semi-float configuration all of the rear loading, be it vehicle weight, cargo, tongue weight of trailer...is all carried at the wheel bearing at each outer end of the axles, from that bearing into the outer-most portion of the axle housing. Combine that with the torque that is ALSO applied to drive the vehicle, it become a lot of load along one single component.

Look at full-float diagram. It has a set of opposing tapered roller bearings in the outer hubs that divide and transfer the rear load onto the spindles of the housing. The torque applied to drive the vehicle is the ONLY load that the axles carry in this design. All of the forces, distributed amongst multiple components.

As others have said it is not about any one thing, going, stopping, or carrying. It's about all of them working together and nothing failing.

Re: What's do I lose???
 

There IS a 6-lug conversion kit for 10.5" 14 bolts (the full floats). Cutthroat 4x4 - GM 14 Bolt FF 6 Lug Conversion Kit The issue that no one has addressed (here) when converting from the 8-lugs to fewer, is you still need a wheel with a large enough hub bore to fit over the rear hub.

Edit: Google found the image, no one I know.

Re: What's do I lose???
 

I believe that was only a sf 14 bolt though.

Re: What's do I lose???
 

If you are set on doing the five lug setup .... I would just go with the stock truck parts , 12-bolt etc.

You can upgrade thru the aftermarket to 13" or even 14" rotors , Put good quality brakes on the rear , it probably already has hydra-boost , make use of that. And then make sure the trailer brakes are working properly. You may want to at least run heper bags on the rear unless you are going air-ride all around.


I have a 96 1-ton crew cab longbed dually that I cut down to a shortbed and then put 1/2 ton suspension on it. I tow a 24ft enclosed race car trailer with it and have had no problems what so ever.

I understand what everybody is saying about sticking with the 8-lug stuff and I have no disagreements with it ..... I was just after a different look and it seems to work good for me.

Re: What's do I lose???
 

I must admit I've never even considered taking an 8 lug to a 5. I think you will be hard pressed to find five lug wheels rated anywhere near eight lug wheels. The minimum weight rating on eight lugs is there for a reason....towing. To each his own, I guess. Call me kooky, but I prefer function.

Jeff

Re: What's do I lose???
 

I can't lie, I have to many parts to go back now. I was just curious to know exactly what issues I could possibly run into. I bought this truck for the sole purpose of having a crew cab laying frame on big hoops. It will probably tow once or twice a month and that's usually going to be local.

It's pretty obvious I know that what I'm breaking a few of the rules that's why I started this thread. Then again for years I've watch guys pull huge toy trailers with those 73-91 suburbans that usually have the 1/2 ton suspension and never heard of a wheel popping of while towing. My trailer isn't over 5000lbs and has electric braking system. I'm not saying it's right but isn't there a famous Nacho truck that pulls the Poncho truck on a trailer and he's bagged.

Re: What's do I lose???
 

i will just cringe at all this

Re: What's do I lose???
 

I swapped my 8 lug stuff out for 1/2 ton parts and haven't looked back yet. In the front I left the 3/4 ton crossmember, and used 1/2 ton parts from the crossmember out. In the rear, I swapped to 1/2 ton hangers (they are different), and kept the 3/4 ton leafs, which are essentially the same as the heavy half leaf springs. I had a rolling frame I parted out. In hindsight, when I shortened my 3/4 ton, I wish I would have just sectioned in the rear of the 1/2 ton frame. I still have not mounted my rear shocks, and will probably have to find a creative way to do so. If you are wanting to run that big of a wheel, I would look into doing the Porterbuilt truck arm rear suspenson. It would solve a lot of problems for you, IMO. I would really like to, but am having a bit of a hard time justifying the $$$ on a truck that still doesn't run. At the minimum, if you are going 1/2 ton rear, I would put in some kind of air bag leveling system on the rear. My old '74 had one, and it towed about anything Scoti asked it to. I hauled a pallet (80 bags) and 16 extra bags of mulch with it, and the truck took it like a champ.

Before everyone gets their shorts in a wad and starts a dogpile on me because I pulled out a bunch of 40 year old 3/4 ton parts and replaced them with new 1/2 ton parts, I never planned on towing anything more than a car trailer (if even that) with this truck. I wanted a CCSB, and the only viable way to do that was to start with a 3/4 or 1 ton and cut it up. I am not a fan of 8 lug wheels, so I pitched them. If GM had built the truck I wanted in a 1/2 ton version, then it wouldn't have been a question. I bought my truck (and the '89 dually that Scoti now has) with the express notion of cutting it up.

Re: What's do I lose???
 

I know people have done this, but look at it from an engineering standpoint:

A crew cab truck will be heavier than the normal 1/2 ton empty. Lets say ~5500 lbs curb weight when done. Add the addtional weight of up to 3 more passengers. 450 lbs + 450 lbs. Now add the weight of a car hauler, which if enclosed is at least ~3500 lbs. Add the car of 2800 lbs. Add fuel and gear ~500 lbs.

Total GCW = 13200 lbs
Total weight in truck = 7080

The problem is that the 1/2 ton gear was never built heavy enough for that loaded GVW. Typical it was around GVWR 6000 lbs total. GCWR is about at the max or a bit more. And this applies to modern day 1/2 ton crew cabs. Look at the GVWR on those. Loaded with pasengers and gas, a big cooler full of beer will put them over weight.

The real big problem here is that you will not really know what you can do withthe truck until it is completley finished and you can weigh each axle. I'd hate to see you build a $40K show truck that can't haul a lunchbox.

The other thought is the legal side. If you get into an accident with your truck, the lawyers can pick you apart for having non-DOT approved modifications done to your truck. I know this is a weak arguement, and nearly all of us would be fodder for it, but be aware that it could happen.

Re: What's do I lose???
 

I'm the first guy to sit here and say bigger is better, but to claim that the op desired setup won't safely haul and do what he wants to do is a bit absurd. The trailer weight is sitting on wheels. Most trailers are set up for 70/30 weight distribution, 70% of the load remaining with the trailer... so he's just dragging it along for the ride. But while we're on the engineering side of things, you can go ahead a double whatever the gvw the truck was rated for because everything was, is, and will be over engineered when it comes to auto related items due to the unknown and sudden change nature involved with vehicles.

Sure, I'd never do what you're planning to do, but I wouldn't feel uncomfortable jumping in your setup and driving it down the road with a loaded cab and car hauler. Stuff will be lighter duty, and will require much more frequent maintenance. Bearings in axles will wear out faster, upper and lower ball joints... I'd even go as far to say that your transmission and gear oil will get hotter than normal and should require a more watchful eye. But, build it how you want it... it'll do exactly what you want it to do... it'll just cost you more in the long run to have to look you desire. But that's the name of the game everyone on this site is playing. Gotta pay to play:waah:

Re: What's do I lose???
 

I'm not a engineer but I'm thinking the only thing that will be a downgrade on my desired setup is me putting the 2008 Dana 44 in place of the 14 bolt and maybe the wheel package that will be on the rear. The off road guys beat the hell out of these things and I don't think I'll be using mine at 50% of the abuse that they put these thing thru. The suspension setup is a four link with bags on the axle and not even an option for me to keep the leaf spring setup. The engine/tranny is a total upgrade also. It's a 6.0/4l80 with ported Escalade heads and special grind cam that will match any 454's torque that I've seen and a rebuilt 4l80 with some goodies.

This bad boy has been sitting around for at least 2 years now. Time to use it.
http://i755.photobucket.com/albums/x...ps25bf0aac.jpg
http://i755.photobucket.com/albums/x...psf4bd8ab0.jpg

Re: What's do I lose???
 

One more thing. When I bought this truck about a month ago I noticed that there were new brakes put on front and back. They stop this big sucka but they leave a lot to be desired. Call me crazy but I believe when I put the bigger 14" brakes on here that it will stop this big ass truck in its tracks (even for a crew cab)...

Re: What's do I lose???
 

Sounds like you made up your mind before asking the question. Adding a modern power plant with big block torque and a trans with "goodies" while you downgrade from a full floater to a half ton semi should be interesting. I guess those silly engineers that designed that full floater with extra lugs and bigger u-joints just didn't get it. Good luck....I wouldn't jump on it with a trailer attached though!

Re: What's do I lose???
 

Point taken. Just asking, maybe I will hear some reasoning to make me go another route.

Re: What's do I lose???
 

Those silly engineers...