Dreaming 74 L18 620: 4spd > 5spd > Automatic

[Cardinal Grammeter]

I'm trying to think how many years ago I found a 80 L20b wide ratio 5spd in South Carolina (I live near Pittsburgh).

I picked it up in SC with my 1987 Chevy Turbo Sprint (!)  

 

Now I'm 71 and the 620 is now my spare/2nd vehicle which means I don't drive it every day like I did for about 8 years.

So the 5spd conversion is moot especially since I don't have the motivation (or strength) to do the job working under jackstands 

So the sensible thing is to just sell the 5spd....

 

THEN, TODAY, I had the idea:  An Automatic conversion would be something I'd actually enjoy.

 

Of course there are a lot of small parts to do a complete conversion which includes steering column, pedals, wiring harness(?)

and I'd probably have to get my passed 70s street racing buddy's VW tuner son to do the job - which I think he would.

 

But it's almost like I'd need to strip a complete auto 620 and I think that would be a 75 and up which may pose other problems.

 

But then maybe someone is looking to convert an auto to a manual and probably is not interested in a 4spd (but then I do have the 5spd).
Of course the logistics of that would be sick in the Rust Belt near Pittsburgh.

The changes are near zero that I will change anything.  Right now my primary car, a 2010 Ford Escape is in the shop for inspection and I've been daily driving the 620.  The first time, the manual was novel, but now I'm sad to say it's an effort I can't afford to spend effort on.  Once I get my primary back, the Datsun will get driven a few times a year which means.....

 

Everything I've just said is just ....   delusional LOL

Agreed?

LOL

Tom
 

[datzenmike]

You'll need an L18 5 bolt flex plate and pilot converter but the later L20B torque converter and or automatic should bolt up. L18s only came on the '73 610 and the '74 710 and 620 so not a lot out there.

 

You shouldn't have to change the steering column it's a floor shift.

 

Just remove the clutch pedal. The standard brake pedal works already.

 

You'll need to run a small vacuum pipe from the intake to the modulator valve on the transmission.

 

Two cooler lines to an RV transmission cooler, or get an automatic radiator.

 

 

[Cardinal Grammeter]

I looked at carpart manual and seems are 2 automatics and also driveshafts.

Sort of late model vs early model automatic setups.

Didn't realize all the autos were floor shifts which makes it easy.

 

I can't remember if my 72 510 had an automatic, my 74 (or 76) B210 deinitely was a 4spd.
If the 510 had an automatic, I have no memories of it being a poorly performing auto - is the 620 auto a "good" functioning auto?  What sort of longevity do they have?

[Cardinal Grammeter]

Man, I just checked car-part.com and you sellec AT or MN and the result if you select AT is ALL transmissions of which almost all are 4spd.  Some don't even say what kind of transmission.  Prices are $100-200 for 4spds.  May not be the best place to get one.  Don't know what the junk yard teletypes could find.

If I could get my hands on one, I just might do it.  But it would be 1-2 years from now at the earliest.

[datzenmike]

The 510 had 3 different 3 speed automatics that were, I believe, some variety of Borg Warner 35s. Only the 411? and the 510 had them. There weren't many with an automatic option all trucks and almost all cars were manual. In April '71 Nissan starting installing their own in house JATCO 3N71B 3 speeds. The 510 automatic is only 26" long same as the 4 speed. All car and truck automatics after the 510 were 31.5" long. 

[Cardinal Grammeter]

Were they all 3spd autos?  How "good" were they?  Did the torque converters flash nicely?  

Simply asked:  Do 620 automatics suck?  Or are they fun to drive?

Studebakers had autos that had Drive and Low that were 3spd.  In D, you pulled out in 2nd and the converter was awful.  The 2spd Powerglide would lift the front end 1-2" when you flashed it from a stop.  The Sudebaker had nothing.  To pull out in Low you put the selector in L and then D when you wanted to upshift, then when it shifted to 2nd, you put it back in L and shifted to D to control the 2-3 shift. 

The Avanti and R-engines had a 3spd shifter and a better transmission called a PowerShift.  Friend had Art Carr redo one and it banged shifts like a Torqueflight.  It was impressive.  I had a PS behind the R2 supercharged 289 in my 1960 Champ truck (had the Lark car cab but bed was truck.  You could see where they cut the car body to fab on the cab back.  Sort of a Franken-El-Camino.

[datzenmike]

They are fine transmissions. You never hear about problems, they are very reliable.

 

The 280zx turbo had a special 3N71B with extra clutches and plates inside and a higher stall speed automatic, all to get the engine revving faster to spin the turbo extra plates and clutches to handle the increased power. It was called an E3N71B You don't need it. I don't think there is any differences in truck and car 3N71Bs.

[Cardinal Grammeter]

Good to hear.  I'll be on the lookout.  Have to see what I can flip the 5spd for, I paid $350 back then.  No idea what prices are nowadays.

[datzenmike]

Don't imagine there are many buyers in Pittsburgh so the price would be higher. Anywhere else you have to ship adding cost to the buyer. Anywhere there are 720s the price would be lower. I'd be leery of a transmission that the seller has not used himself. A rebuild would be twice what you paid for it on top of buying it.

[Cardinal Grammeter]

A parts truck might make more sense but I'm in the Datsun Sahara Desert here.

[banzai510(hainz)]

dont waist your time converting to a auto!!!!!!!!!!!

 

loose 20% HP

and the young guy helping will loose interest and now its worth less

 

Get a Buick cheap with auto and Lowmiles under 2k

Edited May 7 by banzai510(hainz)

[Cardinal Grammeter]

Buick?  engine swap?  all aluminum one?

[banzai510(hainz)]

No, buy a whole car and drive that. for under 2k. Old people LOVE buicks with autos.

a work buddy picks these up cheap with low miles. Nice cushy cars!!!!!!!!

 

swapping this will cost money soembody elses time and loose power

 

I seen 2 people here want a auto in there 521s and they never happen, Nobody want to help as the people wanting it dont really help they just want someone else to do it. Even the Datsuns guys dont want to do it. Not Datsun guys they usually bail out after stuff dont line up right and bail.

Noteven  super Datsun Tech ICEHOUSE has changed a Datsun back to a automatic!!!!!!!!!!!!!!

Edited May 8 by banzai510(hainz)

[datzenmike]

19 hours ago, banzai510(hainz) said:

dont waist your time converting to a auto!!!!!!!!!!!

 

loose 20% HP

and the young guy helping will loose interest and now its worth less

 

Get a Buick cheap with auto and Lowmiles under 2k

 

 It's not that bad. There are some slight losses but the advantages outweigh this. Automatics get a bad rap as they are extremely boring.

[Cardinal Grammeter]

 

3 hours ago, banzai510(hainz) said:

No, buy a whole car and drive that. for under 2k. Old people LOVE buicks with autos.

a work buddy picks these up cheap with low miles. Nice cushy cars!!!!!!!!

 

swapping this will cost money soembody elses time and loose power

 

I seen 2 people here want a auto in there 521s and they never happen, Nobody want to help as the people wanting it dont really help they just want someone else to do it. Even the Datsuns guys dont want to do it. Not Datsun guys they usually bail out after stuff dont line up right and bail.

Noteven  super Datsun Tech ICEHOUSE has changed a Datsun back to a automatic!!!!!!!!!!!!!!

 

I already have a 2010 Ford Escape 3.0 and I like it.  (I'm 71, head injury in car crash permanent bad hangover feeling for all 3 years since crash, have been in crutches for leg issues 3 times in past 10 years.  Have street raced heavy in the 70's.  Have had 3 Vipers at once, still have a modded one I want gone so bad.  Live in a house that is a shack with car parts and collections on shelves to the ceiling.  Sold 3000# of Studebaker blocks, new cranks, cylinders.  And the Super Lark I had for 52 years along with 12 pickup trucks of parts.

I don't think I'd be interested in a Buick although an old 3800 with the don't remember, brown or blue injectors that got insane gas mileage that taxi businesses fought over - might be interested in one of those.

 

Have people that do good work for good money and young tuner friends that love the Datsun truck that would be enthusiastic about working on it.

Do you have any other ideas?  I'm open to all suggestions.

Edited May 8 by Cardinal Grammeter