1971 521

[jon521]

my advice would be to buy that thing if it looks like it's even close to worth it. if you don't you'll be kicking yourself on down the line when your engine goes or you have to do some major repair where it'd be easy to swap. is your clutch slipping on the l16? that's a prime excuse to swap roight there. i couldn't find a collar on rockauto so that might be a junkyard find but i doubt one would be more than a few bucks. clutch kits usually come with the bearing itself though so at least your'e saved that much trouble. i got my engine/tranny from a guy who pulled it all and he was cool enough to set me up with pretty much everything i needed, collar included, but this is something you want to get right the first time so you're not pulling and pushing 3 or 4 times to get it all right. do you know what the engine came from? car or truck? year? either way the 4 speed will bolt right up provided everything between it and the engine has been dealt with. this is basically the problem you're dealing with.... these are mg ones but close enough to get the idea.

 

 

basically it won't go into gear if anything goes wrong because the bearing won't have the full range of motion it needs to engage the clutch properly. all in all though i say gopher it. once it's all said and done you'll love it. beautiful truck btw. you got the height juuuuust right.

 

 

Thanks! :)

 

my clutch isnt slipping yet, but i was planning on replacing it soon, my slave cylinder is all the way out, and it feels like nothing is there. anyways, i found a T/O bearing collar on the link that hainz gave me for like 25 bucks or something, or i could just pull it. except id have to drop the trans to get it, right? i will figure something out.

 

thanks everyone for your help and advice!

['70 521 L16]

have you tried bleeding the clutch? if air gets in the system (which can happen if it hasn't been bled if a long time) it'll start to feel squishy. http://community.ratsun.net/topic/20128-bleeding-hydraulic-clutch/

[jon521]

i havent tried bleeding it. im not too worred about it tho, if im getting this l20b. if i dont get it, then i will bleed the system

[jon521]

so i am planning on buying this motor, and eventually doing a 5 speed, should i replace the 3rd member with something else too, after i do all that?

[wayno]

I have been using 437 gears(stock) in my 71 for several years, I have used 488s and I used 389s, the 488s were great for starting the work truck out, but sucked on the hiway, the 389 gears were great on the hiway, but sucked for getting it started when loaded, empty it was fine. One day i am going to try 411s.

[jon521]

I have been using 437 gears(stock) in my 71 for several years, I have used 488s and I used 389s, the 488s were great for starting the work truck out, but sucked on the hiway, the 389 gears were great on the hiway, but sucked for getting it started when loaded, empty it was fine. One day i am going to try 411s.

 

 

so if i do go to both the L20b and the 5 speed, i might want to go to 389s? you didnt loose take off speed when you were empty?

[wayno]

so if i do go to both the L20b and the 5 speed, i might want to go to 389s? you didnt loose take off speed when you were empty?

 

It depends on your engine, a L16 will have a hard time getting it going loaded, if you have a strong engine you will notice it just a little harder to get going, that is why the manufacturer used 437 gears, these trucks were rated one ton new. It depends on the transmission also, a 620 5 speed might start out better than a 720 tranny, i know the 720 tranny is more hiway friendly, but they had bigger engines in them. If you have a nice strong L20b with a weber or dual SU type carbs on it, and your not trying for a drag strip hole shot off the line, 389 gears with a 720 tranny will be fine more than likely. I went from 437 gears to 389 gears once a long time ago, and I drove to florida from washington and back, I was loaded up with 5 hanggliders and everything I could carry for camping and flying, it was nice on the freeway, it was difficult to get it started from a stop going uphill, when I returned home I had to go back to the 437s, cause I coundn't get it going pulling the trailer with a loaded truck, I could smell the clutch all the time.

[jon521]

i guess i will have to see what 5 speed i get then. i dont have one yet, and dont have a certain one in mind, probably whatever i can get, a dogleg if i could, but whatever i can find. its going to be a step process probably. my plan is to get the L20b, do the valve seals, drop it in with the stock 4 speed, then next the 5 speed swap, then i guess i will see where im at then!

[wayno]

Are you still going to make it to blue lake?

[banzai510(hainz)]

This is my opinion but I think a L16 or 18 is better for the High Way

 

the L20 is a longer stroke and not as needed on the freeway cause the rear diff is so low.

 

Wayno has more experience on this ,but Im just GUESSING, IM just thinking 5500 rpm is EZer on a L16/18 than a L20.

[jon521]

Are you still going to make it to blue lake?

 

 

yes im going to blue lake, before i do any of this. well hopefully i will be going, i just found out my radiator is leaking so i hope i can get a shop to fix it before then!:unsure:

 

 

Hainz, i dont do ALOT of highway driving, its not like i drive to work on the hiway, it is not the reason im doing the swap. id like to swap it for one, either my rings or my valve seals (or both) in my L16 are bad (i smoke every where). two, ive got to do the clutch on my L16. three, more power. but it would be nice to go to be able to go up to portland and back everyone once in awhile, but thats what i was going to get the 5 speed for.

[wayno]

This is my opinion but I think a L16 or 18 is better for the High Way

 

the L20 is a longer stroke and not as needed on the freeway cause the rear diff is so low.

 

Wayno has more experience on this ,but Im just GUESSING, IM just thinking 5500 rpm is EZer on a L16/18 than a L20.

 

5500rpm??, I have never seen 5500rpm, I don't think mine will rev that high unless in neutral, I have had a L16, it would pass DEQ, freeway speeds were the max for it, and it would not go up a mountain road slowly, you went fast or you didn't go at all. The first time it wouldn't go up the hill was the last time it ever went to the hill, the next weekend it had a L20b in it, that was the best upgrade I ever made to that vehicle till i built that truck shortshaft 5 spd. That vehicle is my work truck at this time, it has seen a lot of changes over the years, the only thing left that I bought originally is the cab itself with doors and the seat.

[banzai510(hainz)]

I dont have a Tach but I have at 80/85 mph( 2mins or so) with my 521 L16, stock diff,stock 4 speed but do have a Schneider Asymetric cam and a 38/38.

[jon521]

ya ive never taken my truck to 5500 either. ive barely taken it past 4000. but i think this L20b swap will be good in my opinion, especially if i get a 5 speed. mostly i drive around town. if i get a 5 speed id take it to portland every once in awhile, not very often tho. the L20b swap seems like a win win in my opinion: it takes care of my smoking problem, and i get more power. does that seem correct?

 

 

i cant imagine going 85 in my truck. i think i have some steering bushing worn (or unbalanced tires), because i get a slight wobble from 40-55, but thats for another thread. ive taken my truck going 70, but only for a second or two.

[wayno]

I dont have a Tach but I have have run at 80/85 mph( 2mins or so) with my 521 L16, stock diff but have a Schneider Asymetric cam and a 38/38.

 

 

OK, I got a little excited, I have never tried building a L16 with dual SU type carbs or a weber, I don't know what kind of power a L16 could put out, I know that a cam just takes away torque, I put a RV cam in the engine before the LZ23, that was a mistake, I need torque, but that engine will work well in my 66 520 project. My truck with dual SU type carbs and 280Z valves in the head with a stock cam, did do 100+mph no problem with 389 gears, i have never tried it as it is now, a dually with 437 gears, I did break the speedo needle off a few weeks ago picking up some parts east of seattle wa, but that was with the LZ23 in it. Ever since that day the truck wouldn't go up the hill, I lost all interest in L16 engines, it was embarassing, the datsun wouldn't/couldn't make it up the hill.:(

[jon521]

the more i talk about it, the more i excited i get about getting that engine :hyper:

 

i feeel like my mpg is going to go down the drain though once i get it in and going....:unsure:

[banzai510(hainz)]

Jon. 521s dont get great gas milage just the way it is.If your worried about gas milage maybe get another type of car.

 

 

Wayno. My 521 goes pretty good. For a L16. I think I could take on soem L20s but If I had to do this all over ago I would do L20s, But that all I had at the time and now alot of L20 have cracks in them.

 

I been in a L20 with cam and SUs and it Hauled Ass Maybe cause of the 280zx trans I dont know but it had torq

[jrock4224]

I was just refering to the vehicles that have a L20b with 6 bolt flywheels, as far as i know, you can use the 200sx flywheel, disc, cover, and collar on any 6 bolt crank L20b engine and it will work with any L block transmission, I am not saying to do it, but when you have no money, you take what you can get for cheap. I quit using the dogleg 200sx trannys and all the hardware because it couldn't take the stress of the work truck duties/loads, that is why I figured out how to make a 85 720 shortshaft 5 speed bolt to a L block. I also use the 85 flywheel, disc and cover, the disc is huge.

 

 

yes i am in the process of building that mentioned tranny wayno has helped me alot in sourcing parts.....i cant wait cause the 4sp on the highway is nerve racking....the tranny will go on my l20 when its done and swapped into my truck....

 

maybe you will get lucky like i did jon521... i bought a 5sp l20 and full front suspension and steering including power brake booster and m/c for 200 bucks... was gonna use the disc stuff off the 620 and ball joint but decided kin pin is good enough...

[jon521]

well shit.

 

 

 

 

 

 

 

 

 

 

 

jrock, thats a freakin good deal man

 

 

[jon521]

might be getting a 620 with a running L20b and 5 speed for a good deal, id swap both over.

[wayno]

It's always better if they run, no wait, what are we talking about?:lol: :lol: :lol: :lol:

[jon521]

hahaha:)

 

would a 78 620 have a longshaft?

[wayno]

hahaha:)

 

would a 78 620 have a longshaft?

 

If it is a stock 5 speed, but these trucks are old, and have been surgically operated on so much, it is hard to tell what transmission it is until looked at, and photos are posted of it, then someone with knowledge will make the appropriate decision on what it is. :lol: :lol:

[jon521]

He measured it for me and its 31 inches, longshaft

 

 

[jon521]

if i get this truck, i will be putting both the engine and trans in my truck. as far as the transmission, i know i have to shorten my driveline, and build a custom trans mount. does anyone have any pics of their trans mounts in there 521 with a 5 speed?

 

 

also this truck has 170k miles on it, should i be worried about anything in particular at that kind of mileage?