5-speed tranny

[620connor]

Hello everyone my name is connor and i have a 74 datsun 620 pickup. Here is my question, i want to get some type of 5-speed trannsmission in my truck because i am tired of doing 55mph on the highway. So could any one please point me in the right direction? Thanks, And i will post pics of my truck soon.

[datsunaholic]

Geez, only 55?

 

Don't let the noise worry you- you're only halfway to redline when it sounds like it's trying to fly apart.

 

I routinely took my 4-speed 620s up to 70. Including the '73 with 4.88 rear gears ('74s have 4.38 like most 620s). In fact I had my newly acquired '76 up to 70 on Saturday, and it only has a 4-speed. Will get a 5-speed once I find another one, but the blown-up one in my 4X4 takes priority.

[620connor]

Thanks for the reply, and yeah it does sound like its going to blow up when i take it 70 haha.When i drive in the city i get great gas mileage, but then when i get on the highway and do about 55-60 it sucks gas like a damn v8 and it sounds like its screaming thats why i think i need a 5-speed.

[datsunaholic]

The 5-speed does help with mileage. If you use a 280Z or '77-78 Truck transmission it keeps 1-4 basically the same but adds overdrive.

 

But you need to know which transmission you have to determine which will fit with the least mods. Since you have a '74 it could have either the short or long version.

[620connor]

Thanks for your help i really appreciate it. Okay so how do i tell which version of trannsmission i have? and will the 280z/77-78 truck trans directly bolt up without any problems? Sorry for all the questions im pretty new to this stuff.

[datzenmike]

Again it depends on the length from the motor back to the driveshaft. Early 620s were about 26" long. After Oct. '73, about 4 months into the '74 model year, a new longer 4 speed was installed that is 31.5" long. You need to identify what ya got first or the exact build date of the tag on the drivers door post.

[what]

Go with a automatic tranny out of a 620. Do something different. You can find them at alot of the wrecking yards. I have a buddy at work who put a L20 and a automatic in his 521. He loves it.

[datzenmike]

Buhhhhhhhhhhh, Buhhhhhhhhhhhhhhh, Buhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh... boring :D

[MudThug]

Hey I have an auto that you can have :D I just swaped it out of my truck for a 5spd. You know you want that O.G. status of an auto...

[what]

Hey bro was the automatic in good working order? Do you have floor shifter and everything else to do the stick to auto swap? IF so how much do you want for it? I will take it. Thanks.

[datzenmike]

After Oct. '83 the 3N71B auto was 31.5" long. What year is it out of and what's it going into?

[MudThug]

I just swapped it out of my 79 kc for an 80 280z tranny. I'm not sure tho if I have the taller 5th or not. From what I have read 1980 could be either.

 

If you want it I have everything you need. You will have to put in a tranny cooler or buy an auto radiator since the stock lines fed through my radiator. It was starting to slip a little bit, but wasn't to bad.

[datzenmike]

If indeed it IS from an '80 car it's a 280zx not z, and 5th is either .773 or .745. So not much difference. Both are the tall overdrive.

[MudThug]

That's the thing. If indeed it is from an 80 car. All I have to go from is the guy said... and an old truck shifter works in it. Seems like I read somewhere that the shifters changed in 80, but I could be off :confused:

[datzenmike]

Got a picture of the pass. side tail stock? Post it.