Thread: P10 5th in a B14 trans

I have a B14 trans with mild popout that I was thinking of trying this in for better highway miles.Its a DE basically stock,so I was hoping to see what kind of gas mileage I could squeeze out of it.
I was talking to happynole about this ,and he has a tranny like this in one of his cars.....anybody else have any feedback on this?
Can I just swap 5th and call it a day,or is there more to it than that?
Thanks
Jay

Input Gear - Nissan Part:
P10 5th 32310-D0200 -> 32310-D0211
B14 5th 32310-53A11

Output Gear - Nissan Part:
P10 5th 32341-50J01
B14 5th 32341-50J00

Gear Ratio:
P10 5th is .733
B14 5th is .756

Teeth on input Gear
P10 5th is 45
B14 5th is 45

Teeth on output Gear
P10 5th is 33
B14 5th is 34

Swap both 5th gear assemblies (including bulk ring and slider) and call it day. It will drop your 5th gear 200-300 RPM and every bit helps. Thus it also increases your top speed too .

When I put an LSD 32v trans in my G20 (way back when) I swapped both the fifth gears over for better hwy mileage.

@Cliff - this is another reason why we need a transmission section on the forum

Thanks for the great info!
I am gonna open the tranny this weekend and see what it looks like in there.

Jay LMK know how it goes. If it works and you see an improvement then I might do this also after fixing 3rd.

update
the trans is back together with P10 5th and ready to go.Thanks to @rawdyrawdy for misc parts and a nice P10 5th gear assembly needed to get the trans back in order.
Next step is to swap it back in the car,and see what the difference is.
This was the first trans I took apart,so hopefully I didnt mess it up.LOL

What year p10 5th? Was it a T? Would any of that make a diff?

not sure actually what year or if it was from a "t" I just assumed they were all the same.

I would have to be from a T to fit your B14 tranny, since they are both LSD

are you 100% sure thats how it works? i dont think the 5th has anything to do with lsd..

You CAN take non-LSD gear stacks and drop them into LSD transmissions - that is not the problem. On the 5th - you can not swap only 1/2 the gear (input or output shaft) you need to swap both.

If you are not sure which gearing you have (gear stack laying in an un-labeled box) then you can tell by where the marks are on the gears. If needed, I can add pictures showing the different locations.