K30 Duramax - Body or Engine/Trans Swap?

[Randall12v]

Like title says...

Wanting to do a duramax swap into my newly purchased '84 K30 3+3 4x4


Would you swap the '84 body onto duramax chassis?

or...

Swap Engine/Trans/Tcase and Possible Front Axle into K30 and beef frame up as well?


Looking for Pros and Cons of both.

My mind has been set on body swap, but now that I bought a truck, I'm open to suggestions...

Thanks,
Mark

 

[HotRodPC]

So are you saying you have a complete later model truck with a Duramax powertrain and you'd like to take the body off and put the 84 Body on that chassis?

Not sure how that would work. You'd have to get out the tape measure.

You're not wanting to keep the straight Dana 60 Axle up front?

 

[towjoe]

I'd stick motor and trans in my K30. There's no reason to try and do body swap, way to much work for no gain over just leaving duramax truck alone. Plus the Dana 60 is best part of a k30 to start with other than the looks.

 

[Randall12v]

So are you saying you have a complete later model truck with a Duramax powertrain and you'd like to take the body off and put the 84 Body on that chassis?

Not sure how that would work. You'd have to get out the tape measure.

You're not wanting to keep the straight Dana 60 Axle up front?

I don't have the duramax chassis yet...

I want to keep the stock tcase from the duramax, so I don't think that 60 will work...keep in mind this won't be stock power...

I actually like IFS, for what I will use it for, occasional local brush pulls, drag strip, and street use. I can always do a 60 later into the new chassis

 

[Jims86]

I don't have the duramax chassis yet...

I want to keep the stock tcase from the duramax, so I don't think that 60 will work...keep in mind this won't be stock power...

I actually like IFS, for what I will use it for, occasional local brush pulls, drag strip, and street use. I can always do a 60 later into the new chassis

You can use a Ford axle if you want to stay drivers side drop. It would bolt up to the 84 with very little modification.

 

[77 K20]

I don't have the duramax chassis yet...

I want to keep the stock tcase from the duramax, so I don't think that 60 will work...keep in mind this won't be stock power...

I actually like IFS, for what I will use it for, occasional local brush pulls, drag strip, and street use. I can always do a 60 later into the new chassis

So what trans with the duramax are you thinking about? The ZF-6 or the Allison? Allison is huge- and you might not have room for it if you are putting that into a K30 frame. Might get by with a large bodylift. Not sure. The Silverado HD has a factory "bodylift" (basically a taller frame) to be able to fit the Allison trans.

You mentioned drag strip- you know if you have a Silverado HD frame/chassis and you launch in 4wd your tie rod ends will probably snap on you. They make sleeves for them to try and strengthen them, or make custom ones $$$.

Transfer cases on the Silverado HD can get "pump rub". Might want to check into that. Basically part of the pump will rub holes clean thru the aluminum case on the tailshaft section.
http://www.kennedydiesel.com/detail.cfm?ID=511

And power "won't be stock". I've seen the very heavy Silverado HD frames start to twist with the torque of a modified Duramax. Not sure I'd even attempt to try to harness that torque with a K30 frame. Not unless you are going to box it in with re-inforcements.

Just some thoughts- as I own a K20 and a '03 Silverado HD. I was looking for a Duramax but came across a 8.1L that I couldn't pass up.

Basically I think you'd have a lot less problems just putting the K30 body on the Silverado frame. Then could do a solid axle swap in the future if needed. The 11.5" AAM rear axle is stronger than the FF 10.5" and has disc brakes.

 

[Jims86]

So what trans with the duramax are you thinking about? The ZF-6 or the Allison? Allison is huge- and you might not have room for it if you are putting that into a K30 frame. Might get by with a large bodylift. Not sure. The Silverado HD has a factory "bodylift" (basically a taller frame) to be able to fit the Allison trans.

You mentioned drag strip- you know if you have a Silverado HD frame/chassis and you launch in 4wd your tie rod ends will probably snap on you. They make sleeves for them to try and strengthen them, or make custom ones $$$.

Transfer cases on the Silverado HD can get "pump rub". Might want to check into that. Basically part of the pump will rub holes clean thru the aluminum case on the tailshaft section.

And power "won't be stock". I've seen the very heavy Silverado HD frames start to twist with the torque of a modified Duramax. Not sure I'd even attempt to try to harness that torque with a K30 frame. Not unless you are going to box it in with re-inforcements.

Just some thoughts- as I own a K20 and a '03 Silverado HD. I was looking for a Duramax but came across a 8.1L that I couldn't pass up.

Basically I think you'd have a lot less problems just putting the K30 body on the Silverado frame. Then could do a solid axle swap in the future if needed. The 11.5" AAM rear axle is stronger than the FF 10.5" and has disc brakes.

2" body lifts are working great with the Allison.

 

[Randall12v]

So what trans with the duramax are you thinking about? The ZF-6 or the Allison? Allison is huge- and you might not have room for it if you are putting that into a K30 frame. Might get by with a large bodylift. Not sure. The Silverado HD has a factory "bodylift" (basically a taller frame) to be able to fit the Allison trans.

You mentioned drag strip- you know if you have a Silverado HD frame/chassis and you launch in 4wd your tie rod ends will probably snap on you. They make sleeves for them to try and strengthen them, or make custom ones $$$.

Transfer cases on the Silverado HD can get "pump rub". Might want to check into that. Basically part of the pump will rub holes clean thru the aluminum case on the tailshaft section.
http://www.kennedydiesel.com/detail.cfm?ID=511

And power "won't be stock". I've seen the very heavy Silverado HD frames start to twist with the torque of a modified Duramax. Not sure I'd even attempt to try to harness that torque with a K30 frame. Not unless you are going to box it in with re-inforcements.

Just some thoughts- as I own a K20 and a '03 Silverado HD. I was looking for a Duramax but came across a 8.1L that I couldn't pass up.

Basically I think you'd have a lot less problems just putting the K30 body on the Silverado frame. Then could do a solid axle swap in the future if needed. The 11.5" AAM rear axle is stronger than the FF 10.5" and has disc brakes.

Well aware of tierod, tcase issues and most any aftermarket parts. I've been in the diesel racing/pulling scene for over 7 years. Also owned a duramax a couple years ago. I had a 12v dodge I raced/pulled up until this January when I sold it. As for power, going to have similar config turbo wise as the dodge, s400 based single or compounds, basically push the stock bottom end until it blows, then build a solid platform later.

 

[Randall12v]

As far as trans, it will be auto, either Allison or 47/48re Dodge trans. Leaning towards Allison now.

 

[Randall12v]

I was looking up wheelbase specs, my '84 Chevy CCLB is 164.5" and newer 01-07 Silverado HD is 167", any idea if that length is for CCLB or ECLB?

 

[77 K20]

I was looking up wheelbase specs, my '84 Chevy CCLB is 164.5" and newer 01-07 Silverado HD is 167", any idea if that length is for CCLB or ECLB?

167" is the CCLB
157.5" is the ECLB

 

[Randall12v]

Thanks for the clarification!

 

[Randall12v]

Bought a regular cab 4x4 04.5 LLY Duramax and going to buy a '86 Silverado cab this weekend. Going to try to make this wet dream reality sooner than later. For now plan is to swap body onto 04 chassis. Have a lead for a nicer condition 06 frame, so may use that to get cab measurements started.

Once this gets started I'll start a build thread!