new member questions

[bac]

Just purchased 74 datsun pl620 pickup with 22,400 original miles on it. Hasn't been on the road in a few years, so am getting it tuned and safe before registering. I notice that the engine rpm's are high at 60-75 mph. Have a 4-speed in her. Is there a 5-speed tranny available that will bolt on?? Is there another rearend gearing which might help, if not? Do Chevy 6-hole rims fit this truck? Only 2 original rims. Many questions and looking forward to getting this mini-beast on the road. Drop a line. Bac

[sssr20det510]

yes you can get a 5 speed from a newer truck or 280z, yes chevy wheels will fit

[bac]

Thanks, Senior member. Very helpful. Any idea what year they started making the 5-speed tranny for these trucks?? Will the 280z tranny bolt on?? Any source you can recommend for front signal lenses??

[skunk]

what you want is a dogleg 5speed, not sure on the years from start to end i know they made 77-79 620s with 5 speeds prob made them in 76+ but im not 100% .im a newbe at this stuff to but ive asked the same question myself.make sure if you find a 5 speed its the shorter on the one on the KCs will work but you have to change drive line and move the shifter back, and thus put in bucket seats. but to tell the truth your still going to rev high at 75, these truck are not high speed rigs, they top out at about 80 and thats really pushing it.my 5 speed L20 with a weber carb runs high rpms at 75

[]2eDeYe]

Considering the redline on the L series is 7000 rpm, your probably not reving as high as you think. I got to 90 no problem with my 4 speed and L20.

 

The 280ZX tranny will bolt up, you'll need the shorter front section of driveshaft from a later model truck. The 4-speeds got longer in 75 or so (some one will know the cutoff for sure).

 

Do you have any pic;s of your 22,400 mile truck. I must be in pretty clean shape. :cool:

[datzenmike]

Just purchased 74 datsun pl620 pickup with 22,400 original miles on it. Hasn't been on the road in a few years, so am getting it tuned and safe before registering. I notice that the engine rpm's are high at 60-75 mph. Have a 4-speed in her. Is there a 5-speed tranny available that will bolt on?? Is there another rearend gearing which might help, if not? Do Chevy 6-hole rims fit this truck? Only 2 original rims. Many questions and looking forward to getting this mini-beast on the road. Drop a line. Bac

 

You have a '74 which had an L18 motor and as stated will rev 6 grand all day long with no worries. Sounds worse than it is so the cheapest fix is turn the radio up. You could lower the rear end ratio but this will affect the load carrying, acceleration, highway cruise speeds into the wind or climbing slight inclines, specially with the smaller L18 motor. A better option is to add an over drive 5 speed that drops the revs (about 15%, or 600 RPM @ 4,000) in 5th but keeps the other gears the same.

 

Good news if your '74 was built after Oct '73. (check driver's door tag) It will have the 'new' long F4W71B 4speed which is the same length as the later optional FS5W71B 5 speed that was offered as an option on the '77 and up 620 trucks and some Nissan cars. Here's a list of possible 5 speed sources:

 

 

'77-'79 620 truck. The '77 and '78 have 'taller' first three gears than your '74 but the '79 has the same. Not really enough difference to notice.

 

 

'79-84 Maxima has the same ratios as the '77 and '78 620 truck.

 

 

'77-'78 280z has the same ratios as the '77 and '78 620 and the Maxima.

 

'79-'83 280zx has even taller first three gears and very high over drive 5th gear. Perhaps a bit much for the L18.... it will work but you may not like driving it.

 

Chev and Ford as well as 'Yoda, Mazda, Courier, Trooper and other 6 bolt will fit the Datsun spacing. Check that the center hole will fit the Datsun axle. Not sure about Dodge.

[turbojunker]

The Dodge six lug pattern is too small.

[datsunaholic]

Problem here is it's a '74. It might have the early short 4-speed or the later long 4-speed. They've been found with either one in the wild. I've had one with the long, and it was 100% stock. Bleach had one with a short and swears it was stock. I have a non-stock '74 with a short 5-speed, no idea what it originally had.

 

The best way to figure this out is crawl under the truck. If it has a square steel plate bolted to the bottom of the transmission, it's a short transmission. If it's just the rounded, cast aluminum with a drain plug, it's the long style.

 

This ASSUMES the original transmission.

 

Yes, I know folks are going to say "but there are long versions of the bottom-cover transmission and short versions of the smoothcase transmission". Well, neither of those were stock in a 620.

 

If it wasn't a '74 it'd be easy to say what it had assuming a stock original transmission.

[datzenmike]

Problem here is it's a '74. It might have the early short 4-speed or the later long 4-speed.

 

Corrected