C30 Crossmember question
 

Hi guys, do people pancake the CMs on duallys like is done to half tons>? I have looked for 2 hours and found no info on it,

How bout Z frames on duallys>?

Please direct me to any threads you know of with this info,

Thanks in advance

Re: C30 Crossmember question
 

I should know this as I have a c30 but check to see if your crossmember sits below the lowest portion of the frame. If not that is why you don't see anyone pancake the member as its not needed to lay frame.

If you wanted to lay body there is another whole set of mods you would need to do, chopping the bottom of the frame off and a Z is one way and chopping the top of the frame off and moving the body mounts is another.

There is another great resource specific to duallys and C30s at duallyscene.

Also DblTrbl has a good thread going HERE that has some great info.

Re: C30 Crossmember question
 

I've certainly seen some builds here that were duallys with SFBD.

Re: C30 Crossmember question
 

Thank you Ghost, Im going through that thread right now,

Thanks Slot, Ill search SFBD now :}

Re: C30 Crossmember question
 

It took me a while to figure out what it meant, once I figured out it made sense (pretty sure it's SubFrame Body Drop).

Re: C30 Crossmember question
 

SFDB = Stock floor body drop.

You would section some of the frame height out to lower the cab while keeping the floor stock.

I don't know about C30's but C20's crossmember/arms are the lowest part.

Re: C30 Crossmember question
 

If you tell us your intentions we will be better able to make some suggestions.

Re: C30 Crossmember question
 

Oh no problem, Lower it to the ground ACAP. (as cheap as possible) Leave it unfinished and drive the wheels off it. It will be used like a car for the rest of its life with me.

The lower the better.

Re: C30 Crossmember question
 

I see one problem cheap as possible

Re: C30 Crossmember question
 

I hear ya. I just meant I'l be doing all my own cutting, grinding, and welding. Not opening a big box of shiny porter built stuff.....

Re: C30 Crossmember question
 

I sectioned mine 1.5".

With the frame rails on the ground, my front lower a-arms are about 1.5" off the ground. With my frame @ ride height (factory rails @ 5"), that extra 1.5" means better clearance.

If you're 'Z-ing' the frame, it's not worth messing w/the crossmember.

Re: C30 Crossmember question
 

For what it's worth...I've got roughly $500 in steel so far for my SFBD and I'm nearing completion of the heavy fab work. The cost involved isn't too bad considering the end result, but it's a TON of work.

Re: C30 Crossmember question
 

I initially sectioned a spare crossmember but ended up wanting to go lower. Much easier to do the crossmember than a Z btw.

^^^this. I stop by the steel shop when I am free and grab all the 3/16'' I can find in the remnants. I think I have $40 in my SFBD and the same in my rear notch. I don't even know if I have that much in my Z. I ended up spending $300 in my steering linkage though.

But damn it is a lot of work!

Re: C30 Crossmember question
 

I agree w/this statement. But when you do the work & it's not enough (thus requiring a Z or something else as well), seems it would be easier to just do the Z by itself to begin with.

I like sectioning the x-member because it does not change the position of the motor/drivetrain like the Z will. Helps minimize that domino effect. While it's not 3", the 1.5" difference still can help (especially w/ground clearance @ similar ride heights vs not doing it).

Re: C30 Crossmember question
 

Hi, Ive had tranny and exhaust dragging on the ground on past builds so I dont mind the idea of moving the motor and stuff up with a Z,

But last night as I was scraping my CM getting ready to section it I was going through spare parts,,,,

In the pile I found a sectioned half ton CM, some half ton drop spindles, some LCAs that are already cupped, a later front end with disks, some bags, plates and more.

Im going to bolt in my half ton sectioned crossmember and switch the whole front end to half ton,

Ill get rid of the dually front rims and other problems, (Dually drop spindles were 400 dollars too!)

Ive already mocked this up and it looks like it will work,

Like I said before, This truck is not going to be used like a truck anymore anyway, so half ton front end seems fine,

I plan on doing whatever it takes to get this truck on the ground, it is the longest one, it should also be the lowest one I think,



PS Just to clarify...I wish I WAS opening a box of shiny PB stuff :)

Re: C30 Crossmember question
 

What about the rear?

Re: C30 Crossmember question
 

Ill probably do the same stuff I did to my 70 GMC, Raise the spring perches up, stretch the shackles, raise the tubs and stuff.

Re: C30 Crossmember question
 

1/2 ton or what rear end? It's not a dually anymore unless there's the HD suspension.... Sounds like a CC 1/2 ton w/the stated changes.

Re: C30 Crossmember question
 

1/2 ton? It's not a dually anymore.... It sounds like a CC 1/2 ton w/the stated changes.

Re: C30 Crossmember question
 

Ill leave the dual wheels on it. I like the way they look.

Re: C30 Crossmember question
 

I'd be afraid that you're going to run into some big problems. Not that it can't be done, but there are some significant differences between the c10 frame and the c30 frame, not the least of which is the frame height where the crossmember bolts on. Even Porterbuilt has stated that "the c30 crossmember is an animal all to its own". Nate doesn't sell the c10 drop members to be installed on c30's.

All of that being said, sectioned member or not, you'll still be 3.5" up without a SFBD...and by the time you go through all of that trouble, why not just Z the frame while you have the welder out and truck disassembled...

Re: C30 Crossmember question
 

I strongly urge you to take a step back & re-think your plan. 1/2 ton front components w/5-lug wheels & a 1-ton set-up w/8-lug wheels out back is going to be a head scratcher.

Why not sell the 1/2 ton stuff you have for the front to offset the cost of the 1-ton dually spindles?

Re: C30 Crossmember question
 

The 1/2 ton x-member will bolt right in where the 1-ton unit was. When swapping in a sectioned x-member, the 6x original holes on the horizontal surface (3x each side) remain un-touched. The 8x holes on the vertical surface of the frame (4x each side) require re-drilling for both 1/2 ton & 1-ton.

The upper a-arm mounting studs are 1.2" for the 1/2 ton vs 9/15" for the 1-ton. But they can be swapped out or a 1/2 ton upper arm can be utilized w/a 1-ton BJ swap (only recommended if the truck is going to be used for light duty).

Re: C30 Crossmember question
 

[QUOTE=SCOTI;7413515]I strongly urge you to take a step back & re-think your plan. 1/2 ton front components w/5-lug wheels & a 1-ton set-up w/8-lug wheels out back is going to be a head scratcher.

Why not sell the 1/2 ton stuff you have for the front to offset the cost of the 1-ton dually spindles?[/QUOTE

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Yes the stuff will bolt up, But then Ill run in brake proportion problems, and it will be a fair bit of work to make the truck weaker......Cant do it.

Im headed back out to finish cleanup and proceed with sectioning the stock CM,

Thank a bunch to Scotti and DT for kicking this around with me.

PS anyone know where to get dually drop spindles for less than 400?

Have a good weekend.

Andy

Re: C30 Crossmember question
 

Suspension Source (StreetEdge) that's where I found mine. Seem to be as good if not better quality than the Belltechs I've had in the past.