inboarding opinion wanted

[Leyland]

trying to decide on how to mount my rear 63" springs on my 3500HD frame and looking for opinions... The truck will eventually be lisenced for road use so I don't want something which will be unstable.

Option 1: keep the factory front spring hanger relocated forwarde then use washers to center the new 2.5" wide 63" spring inside the stock 3" hanger opening, then I would build a shackle flip rear hanger to match the front width. This will also allow me to keep the factory 40.5" perch width on my 14ff.

Option 2: inboard my springs under the frame with simple custom mounts welded below the frame and then weld new perches on my 14ff to match the new width. This will give me a rear spring width of approx 30.5" which I figure is too narrow??

[GMCTruxrule]

What is your ultimate purpose for this truck? Hardcore offroad or weekend warrior that doubles as a DD?

Inboarding enables more flex.

Keeping an outboarded spring provides more stability on the road.


I run my springs outboarded just like they came from the factory, and I have stupid flex as is.

[Leyland]

Not a DD, mostly off roading but will see some black top.

I just want opinions if 30.5" c/c between leaf springs is too narrow if I decided to inboard??

how wide is a typical 73-87 1/2 ton frame? 1 ton frames are different again but I dont' know how much

[angryblack]

I went the inboard route but its super tight when you try to add a traction bar.I did it becauxse i cut my frame after the tranny and im running rectangle tubing.
If you have a stock frame then id keep them outboard..The flex from 63's is nucking futts.
I will be adding a sway bar of some sorts. I have a factory one but may just run a spline d unit from stock car products.

[Leyland]

Think I'm going to keep my springs outboarded for now and use the stock front hangers. I picked up some 3.5x3.5 (1/4" wall) tubing this morning and will hopefully get started building the shackle flip this weekend but first I need to strip the frame and shorten it by 48" (to approx 115" WB)

[kitimatdude]

I inboarded and never looked back, it behaves better than I thought it would...

[Twistd Metal]

So my truck is off road only. Does any one have some good pics? I like that it will flex better.

[gmcxt]

Originally Posted by kitimatdude

I inboarded and never looked back, it behaves better than I thought it would...

Whats your perch width? Im thinking about going 32" to match my front. Id like to get close to the flex of 64" springs with 52s to keep a "slightly better" departure angle...

[Grumpy_old_fart]

FRAME widths are the same between 1 ton and 1/2 and 3/4 ton.

spring mount widths are different on 1 tons. 1 tons are narrower by 2 inches on the rear ONLY. one inch on each side.

inboarding provides MUCH more flex, as the axle has more leverage on the spring.

I would leave the springs where they are, and tune them to your application. Its not hard to do, just take a little time. its a whole lot easier than moving mounts.

[77k5]

Don't inboard them.

Yeah, inboarding the springs might seem like a good idea because it adds more flex and all but it really isn't.

Plenty of flex doesn't mean anything if your rig is unstable.

[Leyland]

Thanks for your opinion, after much research I agree with you, expecially with the rig being lisenced for road use. I just wanted to see what others have done and try to get a feeling for what is the narrowest anyone "should" go when inboarding.

I have since started working on my leaf spring mounts and decided NOT to inboard them. If interested, you can follow the thread below in my sig for details to see what I'm doing.

Cheers

[sweetk30]

the 1ton frame on 73-87 is actualy the same width as 1/2 and 3/4 tons. its the frame hangers for the springs. thay are 1" shorter deepth on the spacing outward.

and 42.5" on 1/2 ton and 3/4 ton center pin to center pin

and 40.5" on 1 ton center pin to center pin.

i think 30" would be super skinny and real tipsy . wouldnt leave you much room for a anti wrap bar mount .

[gmcxt]

Inboarding shocks can cause unstable onroad characteristics and inboarding spring does the same. What if you outboard your shocks to compensate for your springs. Seems like it would have some what of an opposing effect...

like this

[]/--||---||--\[]

instead of

[]-||-|---|-||-[]

|| =leafs
/,|,\,=shocks
[] = tires

Sorry my cellphone CAD is weak.

[spidr]

I've never seen the need to inboard my 64s. 8" eye to eye shackle leaned about 60*, with the spring as flat as possibly within reason. They'll flex far more than your truck is capable of where they are. Just tune the shackle hanger when you do the shackle flip to allow the spring to be flatter at rid height.

[MULISHA JP]

My 63's are inboarded and my shocks are outboarded with a 33 inch frame width, []/ ll ll \[] Mine seems pretty stable, but I'm also running a ladder bar. Before the 63's I had 56's in stock location, that worked great too. I guess it just depends on what the trucks main use will be, and what works for you. Thats just my 2 cents.