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.