'81 K30 3+3 short bed Dmax/allison build= making the plans

[rjfguitar]

I bought this 1981 K30 back in 2006 from a neighbor of mine and it has served as my main work/service truck up until late 2013 when it was replaced by a Ford F450 crane truck. It then got bumped to one of my employees as a fuel/lube/light repair truck up until about 3 weeks ago. We found that as a spare/2nd service truck, the K30 just wasn't getting utilized to an extent that was worth being kept around in it's current state. Plans began to convert it to a dually and replace the service bed with a flat bed so that it could haul palletized stuff like chemicals, fertilizers, etc. When we tallied up the cost to convert it to a dually/flat bed/LS conversion, it was economically not a good move and I picked up a 94 F350 4x4 Ford flatbed for less. Details on all that here: http://coloradok5.com/forums/showthread.php?t=321440

So now what to do with the K30? It's been fired from it's day job and put into early retirement and is just sitting here waiting for it's next stage in life. Why...turn it into a fun project, of course.

I am nearly 100% done with my K5, finally finished and should be done by my birthday in Oct which will make me 30. I spent my 20's building up/restoring my K5, and am thinking the K30 will be a great project for my 30's.

Anyway.... enough with the BS and lets get to some pics!

Here is a couple of my K5 for those that aren't familiar with my junk. This is what the final exterior scheme of the K30 will be like, killer paint, full Silverado trim, great tires/wheels and it will be a full frame off resto this time. I made that mistake, I didn't do a frame off with the K5 and now it bugs me. I want this K30 to be stupid clean with the details...like Teck clean... props buddy, you've set the bar around here.

The day I bought my K30: Bone stock 454/400/205. Low mileage, around 90K max.

After I killed the grampa mobile color/wheel scheme:

Couple years (about 2010) the 30 year old interior was getting a little rough, mainly the carpet and a smell that would creep up on hot days that I'd rather not talk about.
Tore the interior out, new carpet and insulation, and new NOS door panels. All my trim and even the dash pad was in terrific shape and was reused.

Here is what a rust free california truck 30yr old cab pan looks like.

So this is basically where the truck sits today. Welder/compressor/tools are all gone and moved to the Fords.

I am going to do this truck in stages, and over the course of a couple years. Stage 1= short bed conversion, stage 2= Duramax conversion, stage 3= axle/suspension, stage 4= full restore. Projected cost is going to be $30K+ for the build

 

[rjfguitar]

I am thinking PPE is the way to go on the Dmax/allison conversion.
http://www.pacificp.com/store/index.php?main_page=product_info&cPath=136_140&products_id=406
$2400 and they do all the harness and programming stuff, including their tuner. Should push 500-600HP pretty easy.

My next issue is transfer case/front axle issues. I am thinking find an NV261 case, which is a driver drop, mechanical linkage case that bolts to an Allison 1000. I believe I should be able to find a dmax/ally/261 out of a truck that is stripped down right? Only the loaded Silverado trucks got the electric shift 263's, right? Trying to get a 205 to work is a PITA, and not worth it, I know you guys love the 205, but I'd rather have a modern shift on the fly aluminum case anyway.

Front axle: The GM D60 will go by by, and something driver side drop will have to work. I am thinking a Ford 90's ball joint 60 won't work because the spring spacing isn't even close enough, right? I am thinking either a D60 out of a later Dodge, or even an AAM 9.25" out of a newer Dodge. This causes another problem, the new style axles are wider than the old axles, so unless I used giant spacers (not an option), the front axle is going to be considerably wider than the rear 14BFF. I'm thinking either a D80 or 11.25" AAM, also sourced from a Dodge.

Suspension: There is no casting in the diff for a leaf spring on the DOdge D60's like an old GM D60, so I would have to go coils. I think that sounds like a good idea anyway. Dodge suspension with about 6" of lift, long arms in the front, and traction bars in the back. Should make it ride much better, my '06 3500 Mega cab with that exact combo rides awesome.

Body/interior: 89-91 radiator support/grille, 91 power mirrors/doors. Short bed conversion. Leather interior with unkown source on seats.

There will be tons of details to work out, frame strengthening, engine mounts, cross members, intercoolers, radiators, etc. For now, that stuff is pretty far off.

Anything to add guys? Anything I'm missing on the overall drivetrain?

 

[Babaganoosh]

This should be a real fun one to watch.

 

[streetrodchev]

I'll be watching this build.

I have heard good things about PPE, but will recommend EFI Live on the tuning part of it.

If my memory is right, the king pin Ford D60 (78-79) is leaf spring and spring pads are about 1/2" closer together than the chevy spring pads.

 

[beags86]

Sounds like your building the truck I have been building in my head for a few years now. I think the plan sounds killer. But I wonder if you wouldn't be better off buying a newer dodge one ton and using the frame/suspension/axles and making the old square fit that. It can be done if your willing to do the work. It might be a better route.

I have been thinking about this, but for me it would be just a lifted road queen so I was thinking about buying a rolled dirty-max and switching body's. I would get good manners and the classic look.

But then I go back to building it the traditional way in my head like you laid out here.

 

[rjfguitar]

I'll be watching this build.

I have heard good things about PPE, but will recommend EFI Live on the tuning part of it.

If my memory is right, the king pin Ford D60 (78-79) is leaf spring and spring pads are about 1/2" closer together than the chevy spring pads.

It's a driver side drop?


I know EFI live is supposedly the best way to go with the Dmax, it's out for the 5.9 common rail Cummins Dodges too and is the best out there, I'm still running an older Bully Dog Crazy Larry tune in my '06 Dodge. I don't really know all that much about the Dmax to be honest, outside of the basics. I know the heads/gaskets are really strong on them, it's the bottom end that blows first. They can flow more fuel and air than the Cummins Common Rail with both in stock form, and I like that it uses Bosch injection parts like the CP3, used on both the CUmmins and Dmax. Given the amount of fuel the stock injectors and CP3 can flow, and the air the stock turbo can push, I probably will stick with a stock engine and just a good tune. 550HP is not hard to get out of them stock, and that IS a LOT on the street. My 505HP Mega Cab Cummins is a rocketship on land.

 

[rjfguitar]

Sounds like your building the truck I have been building in my head for a few years now. I think the plan sounds killer. But I wonder if you wouldn't be better off buying a newer dodge one ton and using the frame/suspension/axles and making the old square fit that. It can be done if your willing to do the work. It might be a better route.

I have been thinking about this, but for me it would be just a lifted road queen so I was thinking about buying a rolled dirty-max and switching body's. I would get good manners and the classic look.

But then I go back to building it the traditional way in my head like you laid out here.

I never even thought of that. It would be a PITA, Dodge rolling chassis THEN swap a Dmax/Ally into that, THEN adapt the old body.

That can be a touchy way to go, I've never done that and we've all seen some baaaad frame/body swaps where you can clearly see that it's not factory at all, where the body sits high on the frame.

 

[beags86]

I never even thought of that. It would be a PITA, Dodge rolling chassis THEN swap a Dmax/Ally into that, THEN adapt the old body.

That can be a touchy way to go, I've never done that and we've all seen some baaaad frame/body swaps where you can clearly see that it's not factory at all, where the body sits high on the frame.

Totally a pain. But you gain things like a MUCH better frame in strength and design. 30 more years of frame technology...
And a ability to buy an out of the box lift kit. Things like that. And yeah it would be tough for sure. But if you have not thought of it then I made my point to for you to think it over. I can honestly agree most jobs like that are completely hack. But I have seen a few good ones...
Judging by your k5 I know if you did tackle something like that I know it would be done right.
Looking forward to seeing this come together.

 

[streetrodchev]

It's a driver side drop?

Yes, driver side drop and high pinion.

I haven't kept up with EFI Live lately, but there is/was more tuning parameters available to adjust on the Dmax vs. the Cummins.

 

[82355]

It's a driver side drop?

Yes. It is what people generally look for when SAS a '88+ Chevrolet.

It is basically the same axle as you currently have, just with the differential on the other side, and high pinion (there are some other small differences.....).

Martin

 

[GWeakland620]

I'm in

 

[Chevy305]

[emoji14]opcorn: subscribed

 

[Babaganoosh]

I originally wanted a dmax in my truck but at the time it had hardly any support and way to expensive.

Please post your progress!

 

[miniwally]

Depending on the year of D-max you may find it hard to come up with a NP261XHD as part of the package.

The NP261XHD was a D-max manual shift transfer case that as the years went on were basically only special ordered.
The NP263XHD was/is the D-max electric shift case. To the best of my knowledge the D-max has never come with what most call the "electronic" case which has the AWD option.

The 261XHD and 263XHD behind the D-max are the same just a different shifter setup.

THe 261HD and 263HD from a non D-max aren't the same as the "XHD" versions.

I would look for a 04.5 up to 07? I think it was LLY and LBZ engine. LLY will need head gaskets and studs, LBZ should be pretty good out of the box. Both are 90% the same engine and with just a few easy things the LLY can be brought up to LBZ status. The turbos are the biggest difference with them.

No LB7 as that's the bad injector engine and anything after the I think 07?' model year gets into emissions like re-gen etc. I know there were Cali. specific emissions stuff for each year as well though.

 

[Cili]

07.5 started the LMM engine, which is the exact same internally as the LBZ just has a different egr setup and has a DPF filter in the exhaust. I assume you're going to run an aftermarket type exhaust and with efi live all the emissions can be deleted. So you're looking for engines from 04.5 to 2010.

 

[miniwally]

07.5 started the LMM engine, which is the exact same internally as the LBZ just has a different egr setup and has a DPF filter in the exhaust. I assume you're going to run an aftermarket type exhaust and with efi live all the emissions can be deleted. So you're looking for engines from 04.5 to 2010.

While I don't disagree I think there are Cali state emissions things he will have to adhere to and I think you have to keep whatever the emissions for that year engine were intact. Hence the 04.5 to as you stated 07.5 model years being the holy grail for him.

I could be wrong about my understanding of the laws too.

 

[Russell]

Sounds like you need an 06.5 to 07.5 LLY or LBZ Duramax engine. Max power, minimum emissions and trouble. Also they have a 6 speed Allison vs 5 speed in the older LLY engines. LB7 are great engines too, but they do have crappy injectors that need to be swapped out a couple times throughout the engine's life.

I wouldn't blow my dough on a PPE harness. Duramax engine harnesses are no more difficult to modify for stand alone than an LS engine. Almost identical actually. They are no more difficult to tune than an LS engine either. I am able to re-program your PCM to enable stand alone operation btw. I don't do power tuning though. I'd recommend team 208 motorsports for that.

You can take a 29 spline input shaft from an NP261XDH or NP263XHD and swap them into a 95+ NP241 to make a 29 spline NP241. This is what I've been running in my Tahoe behind an LB7 / ZF-650 combo. Unfortunately you cannot put a 29 spline input into a 94 or older NP241 (including the passenger side drop cases). The angle of the gear teeth is slightly different between the newer and older cases. While they will mesh together, they howl like crazy and wear out super fast when mismatched. I tried to rip the planetary ring gear out of a newer case to put into an older one once but wasn't able to without breaking the housing. They are mashed in there super tight.

For the front diff, you'd likely be best off running a 78/79 Ford D60 front if you want to stick with leaf springs. If you want to run coils and radius arms I'd just run a newer Ford axle (pre 2005ish IIRC) before they started getting really wide. Unfortunately they have goofy vaccum operated hubs though and the no-spin kits are not cheap. If you want to get really creative you can remove the factory outers and mount older Chevy kingpin outers instead with a newer differential and coil spring suspension.

 

[izzy1776]

For the front diff, you'd likely be best off running a 78/79 Ford D60 front if you want to stick with leaf springs. If you want to run coils and radius arms I'd just run a newer Ford axle (pre 2005ish IIRC) before they started getting really wide. Unfortunately they have goofy vaccum operated hubs though and the no-spin kits are not cheap. If you want to get really creative you can remove the factory outers and mount older Chevy kingpin outers instead with a newer differential and coil spring suspension.

2005 was the first year of the radius arm Super Duty.

 

[rjfguitar]

I am open to an LB7, LLY, and LBZ. I would not be interested in an LMM. Obviously, I prefer an LBZ, especially since I at least right now am not interested in changing out the stock injectors and turbo, so the LBZ's stock capabilities are very much a consideration. Having the 6spd Allison would be nice too.

Smog is a non issue.

What I like about PPE is that they are here in California. Yeah, they are still 300 miles away from me, but worst case I could drag the K30 up onto my gooseneck, and fly down there if I needed help. For those that followed my LS swap in my K5, that is why I went with Pacific Fab since they are 100 miles away from me... and guess what. Something is not right in the computer/harness with my 6L and as soon as work slows down, that K5 is getting loaded up and I'm headed to Gilroy so they can find the problem. I like having that insurance.

I don't want to run a late Ford front axle because of the 8x170mm bolt pattern. I have a bunch of sets of Weld wheels and want to stick to 8x6.5 so that I can move tires around between my Dodges and classic GM's, if necessary.

I'm thinking the old Ford 78-79 60 would be the simplest obviously, but those axles are probably tough to find. A dodge D60 out of an '02 would work well, especially since they lack the CAD system in '02 only.

If I opt for an LBZ, chances are it will be mated to a 263XHD. I kinda figured that, and assumed I will be on a goose chase for a 261XHD.

On the Dmax Chevy's, is the VSS in the rear end like a Dodge and Ford or still on the tcase like typical GM?

If I kept with front leaf springs and went with a Ford early D60, where could I come up with some really good riding front lift springs? I am thinking about 6" of lift.

 

[beags86]

Actually the 78-79 ford Hp dana 60 are easy to find ( at least in my experience) but you got to $$$$$$$$$ pony up $$$$$$$$$$. If you want to really nice set up leaves. a set of Deavers or Alcans can be custom made to your truck, combine with some Quality Shocks and your set.