1966 Datsun Roadster 5 speed swap

[MattN123]

Hello,

New to this forum, and I wanted to get the advice of the people here. I found a 66 Datsun Roadster that has been “stroked” by having a forklift crankshaft installed in the engine. Pretty cool. However, the owner mentioned that there is just too much power for the current 4 speed to handle, and recommends to upgrade to a 5 speed. Before I take the plunge into purchasing this car, does anyone know what 5 speed would fit into this car, along with a ballpark price? Any help would be greatly appreciated, I really like the car but I need to find out how difficult/easy it is move forward with this.

Thank you!

[nismou20]

You can never have too much HP. The 5 spd is a easy swap, many have been done. Minor differences are the Trans rear mount and shift plate above and hole in tunnel needs to be elongated to accept the 5spd. I think the 5spd will complement the 3.90 rear gears nicely too. Do it!

[MattN123]

Oh I see, I totally overcomplicated it. The later models had a five speed which can be swapped into the earlier models. Thanks for your advice and help! Would you happen to know what a good price is to pay for the 5 speed?

[S Allen]

5 speed rebuild parts are not cheap. I was just chatting with Mike Young and servo synchro's go for $170 a pop now up from $120. The 7 main bearings and gasket kit go for around $300. Then you really need to have some that knows how to rebuild them unless you feel up to tackling the job yourself. There is one for sale here on the forum for $250 which could be a good deal depending on what one finds when it is torn apart. Thread is here
viewtopic.php?f=6&t=31650

Also, there is a rebuilt on Flea Bay

https://www.ebay.com/itm/Datsun-Roadste ... 0667.m2042

$3150 plus shipping

There was another one on flea bay for $1400 but it is no longer listed. That would have been a good deal.

In addition to the gear box you need the thicker U20 backing plate or two 1600 backing plates which equals the thickness of the U20 plate. You also need the 5 speed drive shaft which is two piece. The 1600 drive shaft will not work. On the 66 1600 you can just flip the rear tranny mount over and it should work fine with the 5 speed.

Not trying to talk you out of this but expect to spend some bucks. I have a 5 speed in my stroker 67.5 1600 with the 3.9 rear end and love it. That 5th gear comes in handy on longer hauls.

Steve

[Solex68]

If you like the car, buy it and enjoy it. If you decide later that a 5 speed is needed then just keep you eye out for one. Just coming into it as a newbie, I would hold off on the gamble the of unknown condition tranny and the 5 Speed on ebay is a bit pricey. You could probably do better just waiting for a deal, plus you could source the other parts needed at your own pace.
One last piece of advice. These guys are super knowledgeable and helpful. If when you get a car, bring it down to Orange County as we have a few locals down here willing to help. There are some great L.A. resources too.

[david premo]

I recommend you look for a good 3:70 differential, that would give you the drop in RPM you are after. The 4 speed has a lower first gear than the 5 speed and all 4 speed 1600’s with 3:70’s do better. It’s like Nissan got the ratios backwards. Both cars are better off trading diff’s. Must have been a 3 sake lunch when they came out with the ratios.

[MattN123]

Saw that post, was wondering the same thing. I found a website that has u20’s for sale. Any idea what I would be getting myself into with these?

https://www.risingsunracing.com/index.p ... ssion-2000

Seems like a bargain, they are advertised as used transmissions that may have a few things that need to be fixed.

[MattN123]

If you like the car, buy it and enjoy it. If you decide later that a 5 speed is needed then just keep you eye out for one. Just coming into it as a newbie, I would hold off on the gamble the of unknown condition tranny and the 5 Speed on ebay is a bit pricey. You could probably do better just waiting for a deal, plus you could source the other parts needed at your own pace.
One last piece of advice. These guys are super knowledgeable and helpful. If when you get a car, bring it down to Orange County as we have a few locals down here willing to help. There are some great L.A. resources too.

Fantastic advice, I can’t really argue with that! Thank you so much for the tip, I’ll be sure to head over there. What an awesome community!

[MattN123]

I recommend you look for a good 3:70 differential, that would give you the drop in RPM you are after. The 4 speed has a lower first gear than the 5 speed and all 4 speed 1600’s with 3:70’s do better. It’s like Nissan got the ratios backwards. Both cars are better off trading diff’s. Must have been a 3 sake lunch when they came out with the ratios.

Great advice too. I will definetly look into that as an option. I think the first step for me is to actually acquire the car, then move forward with this task. Coming from owning a 67 Mustang coupe, where the parts are so readily available and is a more common car, I got a little worried that I would be buying something that is unable to worked on due to parts availability. I definetly am more comfortable now though.

[raylim]

Hello,

New to this forum, and I wanted to get the advice of the people here. I found a 66 Datsun Roadster that has been “stroked” by having a forklift crankshaft installed in the engine. Pretty cool. However, the owner mentioned that there is just too much power for the current 4 speed to handle, and recommends to upgrade to a 5 speed. Before I take the plunge into purchasing this car, does anyone know what 5 speed would fit into this car, along with a ballpark price? Any help would be greatly appreciated, I really like the car but I need to find out how difficult/easy it is move forward with this.

Thank you!

Hey Matt-
If you have the time, come out Solvang Datsun Roadster Classic held on April 27, 2019 and you'll have plenty of eye candy and advice to solicit that day.
I'll be there as well as 100+ of my roadster friends!
Hope to see you there.
Ray

[JT68]

A few other details regarding the swap. with a 66 you also must drop down the rear trans mount otherwise the 5speed tail housing will be up too high. Another detail is that the speedo cable will hit the 65-66 floor, so you need a little floor modification like the 67.5-70's have. Still, I would absolutely do the swap - transforms the car and certainly worth the cost&effort.
j

[spags1986]

Matt,
I see you are in the Los Angeles area...where about?

[Gregs672000]

Welcome to the family Matt. You truly have found a great bunch of people here who are without attitude or excessive egos and enjoy nothing more than helping out another Roadster owner. Several vendors have done a great job of sourcing parts, remanufacturing some and creating others at reasonable prices given the increasing rarity of the cars these days. There are no "stupid" questions here, no flaming, no BS. If you can, do get to Solvang and you will see. These are great cars as they come, even better with some of the available modifications and upgrades out there. Nothing beats a convertable when driving mountain roads or cruising the beaches. The level of knowledge here is second to none and happily shared. Enjoy!

[shifty]

A 4-speed in good shape is fine for a stroked motor. The stroker is not going to overpower the transmission. 5-speeds are great for keeping the revs down on the freeway!