78 620 Project

[ShootJoeC]

A buddy and I picked up a 78 620 over the weekend for $300. It looked pretty rough in the photos that the guy had on craigslist but we were surprised that it looked at least slightly better in person. It does have a fair amount of rust on the body but the frame is good and the interior, with the exception of the drivers floor board looks decent. The guy we bought it from told us that long-bed, Automatic, with Factory installed A/C is pretty rare. Not sure how true that is. We havent 100% decided what route we want to take with it so we are open to suggestions from you guys. So onto the photos:

 

After a little bit of work we were able to pull the bed off so we could get to the frame to start cleaning that up:

 

 

 

[Dat620guy]

Nice score there. Not a bad price either. If it were me, I'd get rid of the auto tranny, find a nice set of wheels or clean those up and pain them, and lower it down. Can't wait to see what you do with it. :thumbup:

[ShootJoeC]

Nice score there. Not a bad price either. If it were me, I'd get rid of the auto tranny, find a nice set of wheels or clean those up and pain them, and lower it down. Can't wait to see what you do with it. :thumbup:

 

Thanks! Getting a manual tranny is definitely in the plan. We don't know whether to go with a whole new motor/tranny, or just find a tranny from the same motor and put it in. The guy we bought it from claims the motor "runs like a sewing machine" but it didnt have a radiator and the battery is completely dead so who knows if that is true.

[Dat620guy]

Well definitely check that motor out. Could be a really good runner!

[boomstickracing]

even if it's not a runner L20's are pretty simple to rebuild.....and if it came with factory A/C it should have the electric fuel pump :D

[Dat620guy]

That's true my 79 had A/C and a factory electric fuel pump.

[ShootJoeC]

Nice! Is there somewhere I can buy a kit to rebuild the motor or should I just buy the parts at a local auto parts store? Also, how difficult is it to convert from auto to manual on the 620?

[Dat620guy]

There are rebuild kits out there. I've seen them on other web sights, or call your local auto parts store they might be able to get them. I've been told the swap is easy. I've never done it but I know a couple truck people on here have. Try the search function on this sight , I know there were threads about it.

[desert_gold_hound]

There are rebuild kits out there. I've seen them on other web sights, or call your local auto parts store they might be able to get them. I've been told the swap is easy. I've never done it but I know a couple truck people on here have. Try the search function on this sight , I know there were threads about it.

 

The swap (no rebuilding) can be done really easy just have two people instead of one. While I am not a mechanic I have pulled them on one so that I could change out the clutch (now I know how without pulling). If you are prepared and everything goes smooth this can be done in an evening. If there are stubborn nuts or other problems figure a weekend. There is really nothing too this swap.

 

As far as rebuilding I have done this once with help and one thing too remember keep track of what came from where. There are lots of items that if not replacing must go in exactly the way it came out. Have double measurements done and always question the machine shop and check for numbers before bore, after bore, after hone and find these numbers before its done and post so that we can make sure they would be within bounds.

[datzenmike]

By the looks of it it has the mechanical fuel pump on it.

 

You need to get it running before talking about a rebuild kit or motor swap. L motors are tough and many have sat for years and all they need is a battery and gas to get them going.

 

Any 4 speed from a 240/260/280z car after '71 or non turbo 5 speed from a 280z or zx, any 4 or 5 speed from an 810 Maxima, or any 4 speed from a 620 after '83 or 5 speed after '77, any 4 or 5 speed from a 2wd '80 720 will 'drop right in'.

 

To convert you will need a clutch and brake pedal set from another 620, a clutch master cylinder, a hard line to a flex line: a clutch slave cylinder. (I'll assume the new tranny has a clutch arm and release bearing on it) A pilot bushing will need to be installed in the end of the crankshaft.

[desert_gold_hound]

To convert you will need a clutch and brake pedal set from another 620, a clutch master cylinder, a hard line to a flex line: a clutch slave cylinder. (I'll assume the new tranny has a clutch arm and release bearing on it) A pilot bushing will need to be installed in the end of the crankshaft.

 

OH YEA I never thought about all that I was just thinking about the trans going out and new one in. Listen to datzenmike LOL :sneaky:

[ShootJoeC]

By the looks of it it has the mechanical fuel pump on it.

 

You need to get it running before talking about a rebuild kit or motor swap. L motors are tough and many have sat for years and all they need is a battery and gas to get them going.

 

Any 4 speed from a 240/260/280z car after '71 or non turbo 5 speed from a 280z or zx, any 4 or 5 speed from an 810 Maxima, or any 4 speed from a 620 after '83 or 5 speed after '77, any 4 or 5 speed from a 2wd '80 720 will 'drop right in'.

 

To convert you will need a clutch and brake pedal set from another 620, a clutch master cylinder, a hard line to a flex line: a clutch slave cylinder. (I'll assume the new tranny has a clutch arm and release bearing on it) A pilot bushing will need to be installed in the end of the crankshaft.

 

Thanks for all the great info! We are leaning towards getting the motor running and just leaving it automatic, for now at least. Like I stated earlier, the guy we bought it from claims that it runs great so we need to just clean it up a little bit and figure out why it won't start. I am sure its a combination of (hopefully little) things.

 

We are going to start cleaning up the frame first and probably working from the back forward. Out of curiosity, what do most people do for a rear end, just leave the stock one or replace with something else? I wouldn't mind having disc brakes, and while the bed is off now seems like the perfect time to switch out all that stuff.

[desert_gold_hound]

Thanks for all the great info! We are leaning towards getting the motor running and just leaving it automatic, for now at least. Like I stated earlier, the guy we bought it from claims that it runs great so we need to just clean it up a little bit and figure out why it won't start. I am sure its a combination of (hopefully little) things.

 

We are going to start cleaning up the frame first and probably working from the back forward. Out of curiosity, what do most people do for a rear end, just leave the stock one or replace with something else? I wouldn't mind having disc brakes, and while the bed is off now seems like the perfect time to switch out all that stuff.

 

 

I would test engine out with a wire from battery to starter and also one too the coil. This will give you a chance to see if motor is good. (see my project to see how I did it)

 

The disc brakes will be awesome and most would suggest it. I would for one love to see how you go about this and learn from you.

 

Looking foreword to see the trucks progress.

 

 

PS: Your dash looks good other then a couple of spots. Wish my insides was even this nice.

[ShootJoeC]

I would test engine out with a wire from battery to starter and also one too the coil. This will give you a chance to see if motor is good. (see my project to see how I did it)

 

The disc brakes will be awesome and most would suggest it. I would for one love to see how you go about this and learn from you.

 

Looking foreword to see the trucks progress.

 

 

PS: Your dash looks good other then a couple of spots. Wish my insides was even this nice.

 

Thanks! We will be trying that out this weekend. Unless we can find another read end that will bolt up without any fabrication work we will probably stick with drums for now. Thanks! You should see the rust hole in the floorboard on the drivers side, its like a fred flinstone truck. That should be fixed pretty soon too.

[desert_gold_hound]

Thanks! You should see the rust hole in the floorboard on the drivers side, its like a fred flinstone truck. That should be fixed pretty soon too.

 

Do a search on flinstone for these forums I think you would find alot of that. I have had a few other datsun's in the past and two of them came when I lived in Roseburg, OR. They both had rusted through floor panels I found the first one when I was pounding my feet to music (had cruise installed) and WOW what a surprise new a/c during a snow storm going 95MPH (how did I live past this age :hyper:).

 

I bet most non-desert Datsun's have ether rusted through or are almost there. There will continue too be less and less Datsun's every year because of rust. That is why we need more in this hobby so that we may save as many as possible.

[Charlie69]

Nice truck & great price.

 

If you do swap to a 5 speed and the flex plate & spacers & bolts for the flex plate are good I would be interested in talking about buying them. Also the steel plate that goes between the motor & trans & the bottom cover, and the shifter and linkage.

 

Make sure when you get a five speed that you get :

 

The steel plate between the motor & trans

 

The fly wheel & bolts

 

The clutch disk

 

The clutch pressure plate

 

A new pilot shaft bushing

 

Clutch fork, rubber dust boot, & throughout bearing

 

Slave cylinder, adjuster rod, hydraulic hose & keeper, & clutch master cylinder with adjuster rod, and steel line that goes from the clutch master cylinder to the slave cylinder hydraulic hose

 

The clutch pedal assembly

 

The trans with shifter

 

Keep all the bolts also (most of the bolts you will not have & just never know when you might need a bolt) The flywheel & flex plate bolts look the same between the auto and the standard but if you exam them closely the automatic bolts are a little shorter, DO NOT mix them up.

 

Shifter boot

 

The manual trans starter

 

A clutch disk alignment tool

 

Brake fluid

 

Trans mount should be same depending on wha it comes out of

 

Also be sure to chase all the threads before reassembly & torque to proper specs. Flywheel and pressure plate bolts are critical for proper torque.

 

I think that pretty well covers it. Datzenmike would you please look this over and add anything I missed or corect any mistakes.

 

Thank you,

Charlie69

[ShootJoeC]

Once I get back to my desk I will post some updates and new photos but for now just this one: