Planning A SAS, Need Advice

[Horns]

I am currently working on an engine swap into my 98 Silverado. The engine of choice is an Isuzu 4BD1-T. Not only does the front differential fight with the starter for space, But solid axle's are the BOMB! So an SAS it is.

At first I was planning on just buying a kit from a company such as ORU or the like. Not because I am not confident in my fab skills but because at the time I just didn't know enough and wasn't sure about the geometry of it all. Well I've decided to get over that and the last couple months of studying I've become a little more confident that It shouldn't be too much of a hassle to build myself. I am a certified welder and do fabrication for a living so I should have no problem building the stuff, but there are still some things I'm wondering about.

So just a little bit of into, I plan on doing a Dana 44 just because I'm trying to keep this thing as close to half ton as possible. It's just the whole theme of a "half ton diesel" that I'm going for. And I plan on doing leafsprings just for the slimpicity.

Now to my questions.

Is there anything special I should know about the geometry? I've aways heard things about making sure to move the axle foward a bit, but I'm not sure if this is just for linked suspensions or it's something that should be done with leaf's too. what about things like shackle angle, or angle of the springs front to back? Is there anything I should know about that? Is there any special place for shocks? I've seen them in a couple different locations but I'm not sure why or how to choose where to put them.

Ok now about the springs themselves. What ones would be good to use? Is there a factory spring I could get out of the junkyard that would provide a decent ride and are the right size? What about droop over time, is there somehow I can take factory springs out of the junkyard and have them "recurved" if that is the word? Is doing that worth the money or is there a nice set of aftermarket springs the meet the same requirement and aren't gonna break the bank?

Ok one last question while where at it. Is there a way to convert the Dana 44 to 8 lug GM bolt pattern?

Thank you so much for actually reading the whole thing and helping out with the questions with you do.

 

[99z28monster]

I can answer your last question and that is yes. Some of the D44s came as 8lug version under the 3/4 ton GM trucks.

 

[Butch]

Now to my questions.

Is there anything special I should know about the geometry? I've aways heard things about making sure to move the axle foward a bit, but I'm not sure if this is just for linked suspensions or it's something that should be done with leaf's too. what about things like shackle angle, or angle of the springs front to back? Is there anything I should know about that? Is there any special place for shocks? I've seen them in a couple different locations but I'm not sure why or how to choose where to put them.

The front leafs will also cycle back so its still best to extend the wheelbase by a couple inches

Ok one last question while where at it. Is there a way to convert the Dana 44 to 8 lug GM bolt pattern?

If you'd like to keep it 6 lug 10bolt outers will fit D44's IIRC with slight moderation

Thank you so much for actually reading the whole thing and helping out with the questions with you do.

Someone more SAS knowledge will probably correct me but from my understanding what I posted was correct

 

[dirtyhick42]

Almost all of your questions revolve around if the sas will be used for off road purposes or for the bro factor. So if you want to clear all that up then there would be more help.

Or you could just get a 6 lug dana 44, then there is also a 6 lug 14 bolt semi floater that came in half tons so that would make your whole suspension pretty much half ton.

 

[Horns]

I don't plan on doing any extreme offroading but the truck is going to be used as a truck. I will haul my quad/sled with it, use it to haul stuff, and it will be my daily driver. I don't plan on taking it through a 5 foot deep mud hole or do any rock crawling, I would build a offroad specific rig if I ever want to do that, but there's still gonna be some offroad stuff, because it's a fricken truck! I mostly want a nice ride as it is going to be a DD.

The main reason to do that SAS is 1, it need to be done to clear the engine, and 1, it will be a learning experience for future builds.

E: The truck is going to have a FF 14 bolt and I would rather switch the front to 8 lug instead of the back to 6 lug. The only reason I justify this is because the NBS 1500HD's had them and I think 8 lugs would be sweet.

 

[Horns]

Since it was asked on another forum and it's good information to know, My engine weighs about as much as a big block chevy. around 750lbs.

 

[Solid94]

Another good kit IMO is offroaddirect.com. They are based out of Utah and the guy really knows his ****. And no need to convert your Dana 44 to 8 lug the late 70s f250 were 8 lug and are the same bolt pattern as chevy. I plan on upgrading mine to a Dana 60 at some point

 

[dirtyhick42]

OK one more question before I give my full advice size lift and tires are you wanting to run.

 

[Horns]

I'm not really sure. I don't want extreme but I want people with no knowledge to know it's not stock. I want something between a 35-37 tire.

 

[Butch]

Well an SAS alone usually nets +4" on a leaf spring set up, which can clear up to 35"s.