Jump to content

L20b Auto 6-Bolt Pressure Plate


Recommended Posts

Looking to swap to an L20b, but keeping the car auto because Im an OG. Ive got my hands on the engine, but need the pressure plate to mate it with my current B&W auto transmission. Would like all necessary pieces for bolt-on installation. Willing to drive a reasonable distance around Silverdale, Washington to pick it up... or will need it shipped. Either way is fine honestly. Have cash in hand so that I can finally get a bit more power in the 510. Thanks.

Link to comment
  • Replies 28
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Not likely going to work. All autos after April '71 were Nissan 3N71Bs prior to this there were 2 or 3 similar Borg Warner 35s used. The chances that the flex plate from an L20B will work is remote. You can try. The 5 bolt B/W flex plate won't fit the 6 bolt L20B.

Link to comment

I was under the impression that this would work. So the L20b and pressure plate is only a direct bolt in for '71 and later 510's?- I guess I missed that...

 

Edit: Hmmm well... what to do now. Can I swap to a '71 and later auto while still maintaing the same column shifter assembly? Im not sure how each transmission and shifter assembly are connected.

Link to comment

Not likely going to work.

 

I'm saying unlikely. By all means try and find out and let me know. I really hope it works, I just don't know.

 

The 510 only used a column sift on the newer 3N71B for 2-3 months and then all were floor shift. The B/W shift is on the driver's side the 3N71B is on the passenger's side so it will be difficult to use it.

Link to comment

If the column shift for the 3N71B was on the passenger side, can I not make my own shift cable for the early assembly and route it in the same fashion the later assembly? It is cable actuated is it not? I have not specifically looked at the Datsun assembly, but Ive seen other column shifters using that method. Time to look at the FSM to verify.

 

Id rather not spend the money on a plate if it wont work... I dont know too many people that want to stick with auto. I still dont know why I want to... just for nostalgia sake I guess LOL. Thanks for all the help Mike.

Link to comment

Autos rock more than people realize, they just aren't that bad.

 

The 3N71B has a rod going forward from the floor shift. Surely you can rig something.

 

The 3N71B from other 510s are the correct length. The 6 bolt flex plates up to about 81 should work.

Link to comment

Ok, so now Im on the hunt for a full transmission lol... damn it. Ive seen a few floor-to-column shift kits for older muscle cars, so I feel if I can study both diagrams for the B&W and 3N transmissions I should be able to make something work.

 

 

To the Bat-cave! drawing board!

Link to comment

The auto that you want is about 26" long and the only ones that length are from the 510. (I haven't confirmed if the '72-'73 620 automatic is the same short length, probably) The 510 autos should be easy and cheap to find as everyone puts 4 or 5 speeds in and throws them away.

 

Now I don't know if your old one had coolant lines but the 3N71B will.

 

Any L20B automatic flex plate will be 6 bolt and should bolt to the 510's torque converter bolt pattern.

 

 

The most ideal thing that can happen is that you find a 510 built between April '71 and June '71. During this two month period a column shift was used with the new 3N71B. Or to be more accurate the first 3N71B came out in April and the first floor shift came out in June so in between it had to have a column shift.???

Link to comment

No, the transmission was used from April '71 till the end of the 510 run in '73. It's the column shift that was made or used for two months and would make this swap a bit easier.

 

I would take the first 510 3N71B you come across and make something to make it work.

Link to comment

use the search button (LOL) and find this info useful.

 

I didnt know that happened here.

 

Well, maybe I can find a good L18 block local and save some trouble. Mike, can you confirm that it would bolt up to the current tranny in the car?- you seem to be the resident transmission guy around here. Looks like this thread will keep going for a it longer.

Link to comment

The L16 and L18 blocks are virtually the same, so the B/W 5 bolt flex plate will mount to it (L18) and the block will bolt to the transmission case.

 

 

The L20B will also bolt to the case but the 6 bolt crank is a problem. Might be worth while getting an L20B flex plate and see if it works. If you have the L20B anyway it's only the cost and trouble of finding one to try it. I've never heard of this being done so you would be the first.

Link to comment

The L16 and L18 blocks are virtually the same, so the B/W 5 bolt flex plate will mount to it (L18) and the block will bolt to the transmission case.

 

 

The L20B will also bolt to the case but the 6 bolt crank is a problem. Might be worth while getting an L20B flex plate and see if it works. If you have the L20B anyway it's only the cost and trouble of finding one to try it. I've never heard of this being done so you would be the first.

 

Now that you actually say that, I already new that. I dont know how I didnt think of that. Ok, well looks like its time for a built L18 instead. I should be able to pick up the head I was looking at and just find a different set of block/internals. Car should still pick up and go compared to what Im rocking now.

 

Edit: I just realized this thread is in the wrong section.

Link to comment

I sent a 6 bolt flex plate and all a few months ago to Dirt track in Missouri ..but i have a newer floor shifter that we just took out of the 79.. and older 72 ?? floor shifter thats somewhat broken and a floor center console you could have if you think you could use..If you want i could PM the oics of them... but they are pretty scattered about so might take a day or so.

 

 

Confusing sentence is confusing

Link to comment
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.