620KC on 720 bare frame build

[NC85ST]

I would imagine that a good locksmith should be able to re-key it. Or if all else fails, you could try what I did years ago on my 620. I had a ‘73 that I deleted the door handles on. I made it where I could open the door using the key in the lock. In order to do that, the piece on the end of the cylinder had to be repositioned. To do it, I epoxied it in place. I never had a problem with it till the day I sold it. It was tough enough to open the door for years, it shouldn’t be a problem just to unlock it. Epoxy the piece from the 620 onto the 720 cylinder, it will work like a charm.

[EDM620]

Managed to get work done on the door locks and more today. One of the possible solutions was to simply order up a replacement set of lock cylinders, but since that would mean needing 2 different keys, I wasn't keen on that. So after more pondering I decided to hack up the levers and weld the stubs back together.

 

With that done, next was to figure out the puzzle of reassembly sequence. Of course I started that wrong, but got it figured out and got the latch working correctly from inside and out. The lock button + key cylinder however wasn't going according to plan. After taking the cylinders back out & cleaned the crap outta them (literally) they went back in and presto - no presto, still binding up. WTF. Turns out what I had tagged as the R cylinder was actually the L, and once I got that figured out, they worked. Sorta. After torquing up the screws, they wouldn't work. WTF. Backing off the mounting screws freed them up, so somehow they are a bit sensitive to how much torque is applied. Obviously there needs some fine tuning done. Both doors latching and locking correctly now.

The 620 cranks are just slightly longer radius than the 720. The D21 crank is just a hair longer than the 720.

 

Next up was beginning of sorting out the window lifts. I have already cleaned up the corrosion and grunge that was making them hard to operate and now work just like brand new. New window track felt installed on R door, and that's all for today. Tomorrow I'll get the window lift installed + glass in on both doors.

[EDM620]

Got a fair bit done over the weekend (Thanksgiving here) and feeling pretty pleased.

 

Have both doors on needing just a bit of adjustment but are working great.  Windows go up and down, door latches work inside/outside, locks were working but need those last door adjustments before re-test.

 

Windoes sweeps were PITA as none of the clips on the re-pop strips were in the right places. The inner felts required new slots punched out and the felt was stripped and squeezed back in after the new slopts were punched. That was hazardous to my fingers! The outer wipers were way easier, the clips simply were shifted along the strip. The clips themselves though aren't spring steel but I still have the OE strips so can swap them over. GRRRR.

 

Door cards fit up real nice and soon must make decision about how I will trim them up.

 

 

[datsunfreak]

On 9/26/2025 at 10:02 PM, EDM620 said:

Anyone know if the 620 locks can be rekeyed to the 720? 

 

I know my answer is too late, but yes.  😁

 

In fact, they are not too tough to rekey yourself, if you have the (in this case 720) key. 

Edited October 16 by datsunfreak

[EDM620]

5 hours ago, datsunfreak said:

I know my answer is too late, but yes.  😁

Better late than never! My modifications worked out great. Onto the next tasks.....

[EDM620]

With winter already on the horizon (drove through some of that white shit on Tuesday) I'm trying to set up the bodywork schedule with my body guy. I'm OK to send it away for a month or 2 but want it back in my shop before too long so I can finish what I need to do.

 

I really want to be driving it this next spring...

[EDM620]

Did some work relating to the door cards & seats, needing to check fit before I end up with a problem. My seats are from a 2001 Altima and when I mounted up the sliders I didn't have the doors on plus with the idea I'm working on for the door cards meant possible interference. First thing was to eliminate the wiring under the passenger seat (occupancy sensor) which is a hydraulic thing so when I cut the hose it leaked out some viscous liquid all over the floor.

 

With the seat installed and door pull mounted, I was able to determine my clearance to be about 2-1/2" so all is good. With the seat slid all the way fore & aft, I marked out the relative seat position on the door cards - note the door pull is partially blocked at full forward, but no-one is ever going to sit like that - and I now know exactly what limitations I have to work within for my designs.

  

When I initially scooped these seats, I was planning on adapting the 720 dash I had (brown) so the beige seat fabric was ok. You can see that with these seats, the extra "room" of the KC is used up. That no longer provides proper feng-shui in my grey & black interior so either I need to find better fitting seat covers or possibly remove the fabric to dye them. That sounds like a lot of work though...

The generic seatbelts I have do fit properly into the Nissan seat buckles so I won't have to use the floppy ends. The floor anchor ends however pose a problem. The 620 factory mounts are located behind & inside the seat rails, so either I have to run the belt under the rail as pictured or over. The other option is to relocate the anchors - not ideal.

  

 

Time for some sketching to design my non-flat "non-boring" door cards...

[Rustbin]

Maybe attach the seat belt anchor with the seat rail bolt. I like to make door cards from mahogany door skin plywood because my industrial sewing machine can sew through it but you can also just glue the fabric to the card between sections of padding (1/4 inch foam is good) to make your design. 

[Rustbin]

I went looking for a video I saw years ago on making a high relief logo in the door panel but can't find it now but basically you just cut the shape out of landau foam, glue it to your door card then carefully lay your vinyl with the contact adhesive tacked up onto the card using a heat gun to make it flexible and press the vinyl into the low areas with a smooth edged tool. A beveled edge on the landau foam makes things work easier. 

[datsunfreak]

On 10/25/2025 at 8:48 PM, EDM620 said:

possibly remove the fabric to dye them. That sounds like a lot of work though...

 

It is suprisingly easy on most seats. Plus it gives you the chance to remove those plastics and make them black at the same time. 

 

I soaked some seat fabric in RIT dye, and that worked well. If you use the SEM stuff, it works but leaves the fabric a little "crunchy" feeling. The SEM spray dye is great for the plastics, though.

[Rustbin]

Old style seat fabric is held on with hog rings, twist them off with side cutter pliers then put new ones one with hog ring pliers, my favorite pair came from Lordco. Newer seats use various plastic bits that clip or fold on to the seat pan. I personally haven't dyed automotive fabric but do recommend SEM for the plastic parts.

[EDM620]

Thanks for the feedback. I expect to use the dye method once I get the fabric off (new style with plastic clips) and paint the various knobs etc to match up.

 

Playing around with the door cards and might add in some "classy" wood accents - just one of many design ideas running rampant through my head... my wife is interjecting some ideas too. Have to go with the non-sew methods as I don't have access to an industrial sewing machine.

[Rustbin]

I searched again and found three videos showing the ways of doing no sew door panels. The first has the logo idea, the second is from a professional using the landau foam and the third is doing a contrasting inset panel. I recommend the contact cement over spray adhesive where you are attaching to the panel, spray is fine for foam to fabric. I hope these help you bring you idea's to life.

 

 

 

[Z23T]

This guy on YouTube has a bunch of great video's, making all kinds of interior parts.

 

I've had good luck with the SEM interior paint. I painted all of the dash parts in my 510 20 plus years ago and they still looks great. 

 

 

[EDM620]

On 10/29/2025 at 8:54 PM, Rustbin said:

videos showing the ways of doing no sew door panels

I have watched those ones already, well the first and third one, which did give me some of my ideas.  ATM I have about a dozen different layouts drafted out combining 2-3 materials.  I have some material on hand that is "period" appropriate and a few of my designs incorporate what I've got.

 

I did find a seller via eBay that makes pretty decent OE style cards and he would make them in my colour, but overall cost is beyond the budget just for a couple of door panels plus I'd still have the remaining panels to cover anyway and they wouldn't match.

The previous owner on my nephews 68 Cougar redid the door panels plain flat and to me it just looks like crap.

 

17 hours ago, Z23T said:

This guy on YouTube

Yes I've watched his as well, the idea of the door pocket is a nice touch. I have added pockets into the kick panels and rear corners (still in the works).

 

Thanks for the ideas!

[hobospyder]

I have been eyeballing 8garage on ebay since I took the door panels off of the longbed because they are nice looking. Too nice for that truck actually and way out of its budget. I look forward to seeing what you do. 

[datsunfreak]

On 10/31/2025 at 3:00 PM, EDM620 said:

The previous owner on my nephews 68 Cougar redid the door panels plain flat and to me it just looks like crap.

 

On the Galaxie I was working on, we are doing plain flat but wrapped in suede. It think it looks good, but it's very racecar.

 

On my 240Z, I was planning do to plain aluminum panels and wrap them, something like this...

 

[EDM620]

Added colors and patterns make a big difference 👍

[hobospyder]

I have a set of skillard door panels sitting in my house as I attempt to figure out how to accent them because they are to flat and plain. Currently attempting to learn how to use my vinyl cutter

 

Also an idea was brought up by a coworker last night: make aluminum door panels and cover them with the stock vinyl

[EDM620]

10 hours ago, hobospyder said:

make aluminum door panels

If there is enough material, you could run a bead to create a pattern - plus benefit of adding rigidity. A rolled edge would be a nice touch.

 

I used to have a guy who was going to do some panel work for me, but he fully earned the nickname "Mr Unreliable"

[Rustbin]

If they were covered with vinyl what would be the advantage of aluminum?

[datzenmike]

Sound deadening. Some extra protection in a side accident. I've used 3/16" wood panelling but not on a Datsun. 

[EDM620]

3 hours ago, datzenmike said:

extra protection in a side accident

Now that is funny! I might as well be holding a piece of cardboard for all the good that would do. The battery alone on the EV Hummer weighs 2923 pounds. The current Ionic 5 weighs in at 4800 lbs (extended range model) rendering the 620 (or any vintage Japanese vehicle) as effective as a bug hitting the windshield especially in a side impact.

 

Honey, where's my bubble-wrap suit? 🤣

[datzenmike]

'extra' not complete protection. If you want more just roll the window down.

[hobospyder]

21 hours ago, Rustbin said:

If they were covered with vinyl what would be the advantage of aluminum?

extra rigidity in the panel and removes the mdf that could possibly swell/warp with moisture coming in the door

 

using the stock vinyl just to keep the look

using a vinyl sticker to make it different