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Heres yet another 620 4 to 5 speed trans question..


Perez620

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He'll need to find a 5 speed for that one too. Which is a whole 'nother thread about the same thing.

 

 

Automatic brake pedal and manual brake pedal are different from each other.

If it’s a matter of just cutting the brake pedal down then that’s easy. I already have a spare small brake rubber pedal cover for when I need it

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Purchased a 5 speed today out of a ‘77 620. Coming from Oregon so hopefully here by the end of the week :) supposedly it was pulled with 55k on it also a good possibility of a 4.37 rear as well.

 

Thoughts??

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Purchased a 5 speed today out of a ‘77 620. Coming from Oregon so hopefully here by the end of the week :) supposedly it was pulled with 55k on it also a good possibility of a 4.37 rear as well.

 

Thoughts??

 

A good possibility of 155K or 255K on it as the speedometer only goes to 99,999 before 'rolling over' to 00,000 miles. Don't worry it's really a six cylinder transmission anyway. I found one in a scrap metal yard with a '79 280zx body crushed around it. No idea on the miles but I put it into my 620 for over ten years and it's now been in my 710 for 5 more. I would guess 70-80K that I put on it.

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If you have an L20B engine I would find a 4.11 or a 3.89 rear end for it. you will have a better cruibing speed to RPMs.

I was really thinking of a 4.11. Bill has that rear end that I’ve been talking with him about.. now I’m unsure if I should pull the trigger or wait

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A good possibility of 155K or 255K on it as the speedometer only goes to 99,999 before 'rolling over' to 00,000 miles. Don't worry it's really a six cylinder transmission anyway. I found one in a scrap metal yard with a '79 280zx body crushed around it. No idea on the miles but I put it into my 620 for over ten years and it's now been in my 710 for 5 more. I would guess 70-80K that I put on it.

I thought about that as well after I found out it had the supposed mikes on it. I said screw it though because I need one and from what we’ve discussed a ‘77 is a mid ratio trans so it’ll work better for a rear end setup in the near future

 

If it doesn’t last long guess I’ll rebuild it!

 

Btw, what are the actual ratios for a ‘77 5 speed?

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 The '77 620 should have...

 

 

1st.... 3.321

2nd... 2.077

3rd.... 1.308

4th.... 1.000

5th.... 0.864

rev.... 3.382

 

A simple way to tell is mark the input and output spline with chalk. Place in first and have someone turn the input exactly 20 times while you count the output turns.

 

5.5 output is a Wide ratio

6 turns is a Mid ratio.

6.5 turns is a Close ratio... these were only on the '80-'83 non turbo 280zx cars but had a monster 25% over drive which may be important to consider if lowering your differential gears.

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The '77 620 should have...

 

 

1st.... 3.321

2nd... 2.077

3rd.... 1.308

4th.... 1.000

5th.... 0.864

rev.... 3.382

 

A simple way to tell is mark the input and output spline with chalk. Place in first and have someone turn the input exactly 20 times while you count the output turns.

 

5.5 output is a Wide ratio

6 turns is a Mid ratio.

6.5 turns is a Close ratio... these were only on the '80-'83 non turbo 280zx cars but had a monster 25% over drive which may be important to consider if lowering your differential gears.

Great. I’ll try that when I get the trans

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The stock rear end in your truck should be a 4.375.

 

Put the 5 speed in and drive it if you want a higher cruising speed find a lower rear end. If it ain't broke don't fix it.

I wish it had a 4.37 rear but it actually has a 4.625. It originally had a L18 w/ 3spd auto. Swapping a L20B now so that’s why I’m really considering changing the rear end

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The '81-'82 automatics had them.

Question.. whats one way to determine a 5 speed vs. a 4 speed from a 620 by just looking at the exterior?

 

Is there a specific number on top of the bell housing that distnguishes the two?

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