My first '78 620

[BiLiONS]

Hello everyone! I recently purchased this 620 that has only had one owner since its purchase! (I'd be the second ofc)

 

It has 96k original miles.. im so stocked! It's completely stock and it's definitely mis matched in different areas.. runs and drive but I'm gonna work on it as it is.

 

Any suggestions on first steps? I'm definitely going to get it tuned up this weekend. Thinking about struts since it bounces with a slight push.. im open to suggestions, ideas, thoughts and everything! 

[620slodat]

That looks like a good one. 

620's and 720's do not have struts. The front end is a torsion bar (in place of a spring) and shock. They are good, until you have a location problem. The biggest problem is camber (I think, maybe caster, I always get them mixed up), anyway it is the in or out of the wheel at the top of the fender. If you take the lowering route to the extreme it will look like that wheel is closer to the other front wheel at the top of the fender. It's not the torsion bar, it would look similar if it had a coil spring instead of a torsion bar. The upper and lower control arms are different lengths.

 

Don

[banzai510(hainz)]

Buy a cheap KYB GR2 gas shock and that should take care of the bounce

[datzenmike]

Yup, new shocks. Best ride and handling improvement for the buck.

 

There was an optional sway bar for the 620. Holes and threaded holes are already there. You'll have to source them from a wrecking yard.

 

Use a magnetic level vertically on the front rims and lower till the camber begins to tilt in. Any lowering will pull the tires inward (toe) at the front so when done align it.

 

 

[BiLiONS]

Hey everyone! Been a while. 

 

So, ill start by saying thank you to explaining the suspension components! I really only want to lower it maybe an inch or so but that would be one of the last things I want to do since its not a priority. I got the datsun driving perfectly and I use it to commute 30 minutes to work and back over a bridge.. little sketchy but its fiiiine. Sometimes I haul my rebel in the bed when I gotta move it from one side of the bay to the other. 

 

https://imgur.com/a/R7T2ckW

 

Recent picture I took of it and current interior

 

Changed out:

- the old wheels and put on these wider wheels with way newer tires

- wasn't a fan of the bigger side view mirrors so I installed these smaller chrome ones

- inside was stripped of the old carpet and since it had mismatched seats I took those out and put in some leather seats that are very comfortable

- I grabbed some free carpet floor mats and put them inside just for looks

- Original steering wheel was cracked and super thin so I got a grant steering wheel and installed it with the horn wired up too 

- Did the basic tune up and it idles fine, picks up fine, and runs fine as far as I know

 

I use this truck 2 or 3 times a week and its done pretty good for me. Only concern I currently have is that after driving for maybe 10 to 20 minutes, I start hearing a light ticking noise. As revs go up, ticking noise gets quicker. This started after the oil change.. or maybe before that but never noticed. I used Rotella T4 15w-40.. could that have cause that noise to start up? Its a light ticking as the car idles and drives. If it sits for a few hours and turns on, the ticking isn't heard. Its only after it warms up completely If anyone may know of possible causes or what I can do to fix any issue this may sound like, please let me know. I love this thing.

 

[datzenmike]

 

 Nice picture

[Stoffregen Motorsports]

Awesome.

[banzai510(hainz)]

maybe try a different oil filter.?Im guessing myself.

 

I would ck the valve lash myself.

 

 

great your keeping this on the road!!!!!!!!!!!!!

 

cheap gas shock will help the bounce. But not Moroematics NOT that one.

Edited July 2, 2024 by banzai510(hainz)

[datzenmike]

What's the difference between cold and hot running? Oil pressure is highest when cold. Clearances such as valve lash are wider when cold.

[BiLiONS]

Hey all! Sorry for disappearing!

 

Well, as far as I've driven it and listened in, I am going to just assume its old truck noises.. it doesn't have any issues running so I am going to cross my fingers and hope its just a one off thing with the engine tick.

 

Recently though, my brother decided it would be a nice fun idea to drive the truck without asking me beforehand.. if he had asked, I would have told him about the air in the break lines... lo and behold, he crashed the damn thing. I had replaced the damaged fender on the left side already, and he decided to crash the RIGHT fender.. oem and perfect condition too.. god I hate siblings.

 

After that, i lost a lot of motivation for the resto project 620. The accident threw off my alignment and suspension so i have to figure that out now. 

 

So, engine wise, the original carb started leaking gas. I noticed smoke coming out of the engine bay and popped it open to see drops of gas hitting the headers (?) making it evaporate. Crisis averted though as I turned it off very fast and decided to say fuck it, lets buy a weber. I'll replace the original carb with the weber and see how I do. Anything I should be mindful of or ensure? Appreciate all the help.

 

I also decided to downsize in the wheels department and got some 16's with 215/55/16 tires. They're small, but I honestly like the old school look more then the big wide tires. Juuuust need spacer to clear the bore.. the new rims have a smaller bore than the datsun recommended size. Will be dropping the bed about two inches and adjusting the front to match the rear.

 

I'll be making the door cards on the Datsun out of aluminum and will also be installing a bed liner to clean up all the rust and just make the bed nice and uniform. Also bought a big ol vinyl cutter so gonna replace the faded stickers such as 'King Cab' on the truck in the near future after painting it the oem color again. Nice and shiny.

 

Of course, any and all recommendations and insights are welcome! I'll be on here more often now that I got motivation for my little truck again.

[datzenmike]

215/75R16 geez that's almost 3 inches larger diameter than stock. This will hurt your performance slightly and your speedometer will be reading lower than actual speed. A good 10%! When at 45 you are doing 50. A 185/65R16 would be very close to stock diameter and width of around 7.5" Things that should maybe have been thought about earlier.

[banzai510(hainz)]

I need to get out of Datsuns now

[banzai510(hainz)]

On 3/16/2026 at 3:33 PM, BiLiONS said:

i lost a lot of motivation for the resto project 620.

3 post and lost interest I think this is a new record

 

seel it to somebody for that will apppreciated this truck or use it for parts. sell 400$

Edited March 19 by banzai510(hainz)