Attention DatsunMike or any other Datsun guru

[newsouth]

First of all, I am NOT an experienced mechanic. I am a handy 50 yo man, but rebuilding cars has never been a challenge that I have yet encountered. 

Secondly, I love 620s.  A ‘72 Kermit green 620 was my family’s second car and ultimately my first personal vehicle. 

I have owned several 620s over the past ten years. I’ll find one, buy it because it has it’s unique qualities, and then sell it because another one catches my eye. 

I currently own two KCs. One (‘77) is currently being readied for a complete body/paint refurbishment. I could elaborate on it at length (SR20DE swap, Heidt’s front end, Ford 8” rear end, Lokar shifter, disc brakes, Stewart-Warner gauges, Vintage Air, etc.), but I’ll save that discussion for later. 

My other ‘78 620 KC is a VERY nice original. 

My question: How difficult would it be to transfer the body of my ‘78 to a late model Nissan 4WD? I really want the appearance of a ‘78 620 and the functionality of a modern 4WD truck. 

 

Your thoughts? Thank you in advance. 

 

-Keith

 

[datzenmike]

? I don't think I'm a guru. The more you know the more you know you don't know.

 

The 620 KC will fit the 720 KC or Long Bed frame. I don't know about newer truck. The wheelbase would need to be very close or the frame would need to be shortened/lengthened. The 620 steering column and box is one piece so... probably you would need to replace the 620 column with the donor truck's. You would want the donor truck master, booster and anti lock brakes, connect the electrical and gauge senders. Will the VG33 or whatever, (a 4 cylinder is likely best) engine and all it's associated gear, fit within the narrow confines of the 620's engine bay, or the larger rad? Lots to think about....

[Stoffregen Motorsports]

Awww, come on Mike. If the shoe fits...

 

Body swaps are a lot of work to get done right.

 

Question - what is your intended use for this 4x4? Are you open to a solid axle up front? If you actually want to use it, and also want a bit of a lift with 33" or larger tires, I would consider a solid axle from a Toyota. There are a couple guys here on Ratsun that have 620 solid axle trucks. They can probably lend a hand with pics and info.

 

I'd love to help you build this truck, but we're on different sides of the country.

[Bleach]

It sounds like your 1977 truck is getting a modern drivetrain and suspension. You said you want your 1978 to have functionality of a modern 4x4 so does that just mean you want a fuel injected engine, modern 4wd transmission, independant suspension in front, and a normal solid axle in rear?

It sounds like adding items to your existing 1978 truck would work better. The 720 truck is the only model that is almost the same size frame and body. After that, the Hardbody and Frontier were a bit larger. The most recent version of the Frontier is nearly the size of a full size truck from a few years back.

 

Is a 1980s 720 4x4 modern enough? I guess you could run the drivetrain from something like that but use the KA24DE fuel injected engine from a Nissan Frontier. That might give you want you're after.

[newsouth]

Guys, I seriously appreciate your feedback. 

My goal is to have a KC 620 that I can comfortably cruise at 75 mph and can shift it into 4WD when needed. 

For me, the 620 body [style and size] was ideal. 

I want to transplant the body of a KC 620 to a modern Nissan truck and maintain the 70s feel. 

I need to know what modern Nissan truck would be the ideal donor for my ‘78 KC 620. I also need to know what roadblocks may kill my project. 

I’m going to research the wheelbases and tranny lengths and all that, but I really want to know if there is s critical element that is a show stopper. 

DatzenMike/Stoffregen/Bleach - you guys are legendary and I genuinely want to learn from you. 

Please help me find the particular Nissan truck that would be the most efficient donor for my KC 620. 

 

Thank you!

 

 

 

[Bleach]

The frame rails are simply wider apart, the engine compartment is longer, and the cab is longer on the 1987-2005 Hardbody and Frontier. It just seems like a really bad fit to try to mount the 620 body onto those frames and then shorten the wheelbase of a Frontier.

 

Now, the 2006+ Frontier is out of the question. They are just big trucks and go even further with their size.

 

I'd say go for a 720 4x4. The 720 kingcab is a longer cab than the 620 kingcab but not by too much. You might still run into the issue of the rear wheels being too far back. Hopefully by only 3-4 inches.

Certain years of 720 have different gears. If you want to cruise at higher speed, get the trucks that had a 3.9 or 3.7 gear ratio if possible. (those might only be in the 2wd) Then take the underpowered Z24 out and install a KA24DE from a 1998-2005 Frontier. Then again, some people do take the 620 body and drop it onto a Chevy 4x4 truck frame. :)

 

I don't know anything about the different transfer cases on the 720 4x4 but maybe the later years had better quality ones... 

 

[datzenmike]

The720 is even slightly wider, the D21 wider still. The mini truck is becoming a 1/2 ton chevy!!!!

 

The 720 has a divorced transfer case so any engine can be fitted to it by making the correct driveshaft, however they are not unbreakable. The D21 has transmission and transfer case together and came with KA or VG six cylinder engines. 

 

I put a 620 KC on a 720 long wheelbase frame and it fit very well as there are a lot of similarities. I think the axles on a Hardbody would stick out too much.

 

. 

[Stoffregen Motorsports]

For a simple and elegant daily driver, the perfect combo would be:

 - 720 4x4 chassis, power steering, power disc brakes and balljoint suspension

 - D21 KA24E and trans with married transfer case (the divorced t-case is kind of a piece of crap)

 

Not sure about the front output on a D21 t-case. Is it on the same side as the 720 front diff?

[newsouth]

Okay, so I think the consensus is:

1. Donor should be a 720 KC 4WD.

2. Drivetrain should be D21 KA24E with the married transfer case from a ‘98-‘05 Frontier. 

 

I want to keep the 620 interior exactly the same. Ideally, the end result will be a ‘78 620 with all the conveniences and functionality of a modern 4WD. 

 

Guys, again I appreciate your input. 

 

*One other thing, how is the easiest way to post photos on this forum?

 

[datzenmike]

22 hours ago, Stoffregen Motorsports said:

 

 

Not sure about the front output on a D21 t-case. Is it on the same side as the 720 front diff?

 

Same side. (drver's)

 

The T-100 trans case is ok for a Z22/24. I would definitely recommend the KA trans/transfer case combo from '90 and up.

[Stoffregen Motorsports]

1 hour ago, newsouth said:

 

*One other thing, how is the easiest way to post photos on this forum?

 

Third party hosting site. I use Photobucket, but I pay for it, and it is hard to use, and it sucks, and they are scumbags...lots of reasons not to use Photobucket.

 

Imagur, Flickr, Image Shack, Dropbox....

[wayno]

I do not know your capabilities, but the easiest way to do this would be to find a 1980 thru 82 Datsun 720 regular cab/short box 4wd truck as it is basically the same frame except for some small differences, put the 78 kingcab onto the chassis/frame which really is only hard the first time and get it derivable, then on to the hard part which is to shorten the box, the easiest way is to just cut a piece out of the middle between the fender well and the front of the box and weld it back together, the best way would be to drill the spot welds holding the front vertical box pieces on the box which will be time consuming, then cut the front of the box off the proper amount and weld the front of the box back into position, then mount the box and figure out the gas filler.

You use all the 720 chassis stuff as much as possible like the e-brake cable, you also use the 720 steering column, the easiest one would be the non-tilt version.

There is a lot involved in doing a cab transfer, one is the laws in your state, sometimes it is just better to put a Toyota axle and a divorced transfer case under your existing frame that way all the numbers still match, but you need fabrication skills to do that while doing it the way I described above does not take a degree in welding, sheet metal welding(actually tack welding), and custom made parts like transfer case mounts, drive lines. and leaf mounts amoung other stuff I have forgotten about.

Edited January 13, 2019 by wayno

[datzenmike]

I would settle for the later '83 and up that has better vented disc brakes and booster. The rear drums are also self adjusting, the very earliest 720s weren't. I would skip the '80 as the front differential is on the passenger side. If going to the later D21 Hardbody or w/e the transfer case front output is on the driver's side. All '81 and up 720 front differentials are on the left of driver' side.

[Bleach]

On 1/13/2019 at 7:44 AM, newsouth said:

*One other thing, how is the easiest way to post photos on this forum?

 

 

The "post image" website address changed slightly, but I think this video still shows you how the process is done.

 

 

[wayno]

All I know is at some point in the 720 run the rear axle gets wider while the early 720 I have no issues with my 521 cab having the tires sticking out of the fenders using P195/75R14.

My lowered 520 was put on a 1986 chassis, the rear tires 185/60R14 and they barely fit in the rear, the fronts with drop arms did not fit except pointed straight forward until I used P165/65R14, since then I made another narrowed set of drop arms that work with the 185s and I suspect I could put the original drop arms back on and still be able to turn without the tires hitting the fenders, P195s will not work at all as the tires stick out too far with the 1986 chassis.