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Another 350Z seat install (for tall people)

Aero Z

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I originally did the Acura Integra seat swap when I did my LS1 swap and it was just ok. Then I came across some 350z seats pretty cheap so I decided to use these. They were more comfortable and the orange mesh goes well with my orange car.

The other 350z seat install thread does a good job of showing one way to do it and it has good pictures of the seats in the car. So go here to see how others have done it.


That method keeps the 350z sliders in place then just weld a bar stock across then attach the 240z sliders. This adds some height to the seats and requires more welding for sure. IMO my method is much stronger/stiffer since the metal on the 350z sliders is really thin.


Since I'm 6'6 (220lbs) I wanted to get them as low as possible.

Here's the steps and pictures that explain what I did.


Remove the 350z sliders by cutting them in the right places. This was kind of a pain. Just cut where you need to pull them off. Should take two cuts per track.


I used some 1/8 x 2 flat bar steel stock cut to the proper width to span the width needed. Leave a little extra so you can weld on all sides. In the front this is very easy as its just flat. In the rear you can see that you need to bend it to match the butt pan of the 350z seat since it sits below the bottom of the metal sides. This is what makes the seats sit as low as possible. I used some scrap aluminum bar I had around to make a template. You'll need to match it pretty closely because the width the 240z seat tracks need to be puts them just outside the bends.





You will need to get the fore and aft spacing of the cross pieces correct on the seat so the seats sit as far back as possible. If you're tall and the only driver you have some error slack but since my wife is 5'4" and wants to drive the car it still needs to go as far forward too. It was actually different on mine because my passenger side seat tracks wouldn't go all the way back. So you can see in the pic the front cross piece is as far forward as possible. On the drivers side it was about 1" from the end of the 350z metal sides.





These seats sit as low as any seats could easily go without any structural mods. The original seats (minus the height adjusters) sit about the same height because they're very similar mounting. If you wanted them to sit higher just use the same height adjusters off the original seats. With my height I still have plently of room and could wear a helmet if I needed to. You'll need to do some trimming on the plastic side garnish pieces of the 350z seat as well to make it look factory and fit.


I'm using the 240sx rear seat belt mod for belts. http://forums.hybridz.org/index.php/topic/97131-fitting-240sx-nissan-retractable-seat-belts-in-the-s30.

I simply took the buckle from the 240sx and bolted it to where the old 350z buckle receiver went. If you're using your original 240z belts you should just be able to keep them bolted to the floor.

Edited by Aero Z
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  • 8 years later...

Digging up an old thread....


Great writeup with pics. I am 6'0, but wanted to keep the seats as close to the floor as the stock seats (especially for helmet reasons), plus, like you my wife wants to drive on occasion (5'1"), so I need to retain adjustable seat position. 


Hopefully picking up a cherry pair of cloth manual 350z seats tomorrow. 


Unfortunately for me, my stock seats got tossed by a buddy who didn't realize I would need pieces of them.

Edited by Cable
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I don't think I have pictures, but I'm doing basically the same as above using RX8 seats except I'm using the mazda sliders, so my adapters go between the sliders and the chassis.


I just bent a few pieces of steel strap to mount the new sliders at the same angle as the stock seats and then I'm going to weld on a few cross bars of the same material to adapt to the wider rails of the new seats.


Looks kinda like this from the side

/        |__


I'm going to have to do something like above to clear the seat pan, but I think I'll end up with seats just barely lower than stock with a lot more bolster and most of the slider range from the rx8, which being a 2+2 car is a lot of range. I'll likely gusset the 90 degree bend on the rear part of my adapters as well just for some added peace of mind, but I don't think they're going to flex once they're all bolted in.

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  • 1 year later...

Hey Aero Z just want to thank u for the writeup.  Same method worked great for me on set of 370 seats I got a deal on.  Im not the best welder so managed to do a bolt on install.  Some pics included of that as well as the trim line I had to do on the plastic. 




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  • 1 year later...

Took the seats out of the 350Z today, and moved the car into her (my mother) backyard, out of the way for her winter driveway access


Have to cut a section of the harness for each seat tomorrow


Power, heater & SRS


broke the pass seat switch, bent the bracket - seat was behind the car & I backed into it  image.gif


Thankfully, I didn't damage the seat itself



Cut off the rail standoffs



2 rivets & 2 spot welds for each leg


Assuming these elements are for crash protection - I may want to add them back




Put some paint on the ground-down areas, to protect it for now


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Took the seat power & heater wiring out of the 350Z




Couple of issues. I neglected to mark the fore/aft setting of the outer rail before I cut off the standoffs, and observe the stock rake of the cushion in the 350Z.



What I have found is that the 350Z rails sit precisely outboard of the 1/8" 1.5"x.5" C channel rails I'm making.  Figure it's significantly more rigid than flat stock.




I'll possibly add cross braces of C channel. I'll tack the 350Z rails to these first, after I fill-weld the cuts. 


doesn't look like the seat cushion / base will hit anywhere at this drop though


Have to figure out if I can dismantle the rails to allow for welding the new with the existing. Don't want to melt the plastic guide inserts.





Recliner is up against the 280Z belt reel guide, without the protective cover. Probably won't be keeping the stock belts. I'll leave the trim off until I figure that out.



up against the ledge, pretty much


tangs for retaining outer cover have to be removed, hits the cross frame




Placement.  As far back as it can sit, cushion is still further forward than the driver's seat



Like this, it sits lower than the stock seat cushion , feels comfortable as is. 


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Had a few hours today, so I filled the pie cuts & added reinforcing washers on the PS rails. Cut the 2 DS rails & started welding them also - looked back to check that the DS was the same setup





welded a bead on the backside where I had bent the plate








tools for cleanup




Added a rib across the top side of the bend also






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23 hours ago, madkaw said:

Been rocking these seats for years on my Z . It makes riding in my Z so much better for this old mans body .

Nice work!


Thanks for documenting yours - it has been most helpful. Being a new Datsun owner, I'm always surprised at the constant revisions to things on these - I didn't notice at first that the 240Z seat mounting cross frames are quite different!


Did you take any pics of the Wesco belt mounting, or is it self evident? I'm wondering if they still have the neck choking effect of the stock belts - but I'm 5 6", so they may not be an issue for you.

Edited by HusseinHolland
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  • 2 weeks later...

Back in the 350Z seats into the 280Z. Seat belt reel will (hopefully) be relocated to strut tower, like the later 77-78 280. Welded the rails I made to the 350Z rails, Checking that the seat was level to the car before tack welding. Used an weld mat to protect the interior. Removed to finish the welds. Wired the passenger seat (fore/aft only). Have to wire the seat heater



Looks good herePXL_20231225_182403487.jpg

I didn't seam weld these. There is a plastic guide rail inside that may (did) survive some heat, wouldn't trust it to survive a bead, especially on top 


Test fit after welding to check for distortion /displacement due to welding, all good sits level with no wobble in the rails


Testing wiring for seat fore/aft. I bought used 350z heater switches, however it will be easier (I hope) to rewire the seat grids to the aftermarket relay & switches I already have in place


Full forward settingPXL_20231225_205953444.MP.jpg

Seat sits substantially lower than stock height. Furthest possible recline in full rear positionPXL_20231225_211852177.MP.jpg

Wesco reel will hopefully go here. Does not feel like there is a metal plate under the cover, which may actually make it easier 



A beating was in order. Not really happy about pummelling the perfectly good and clean tunnel, so I was gentle at first & used a mallet & block of wood to gently invert the bulge. Problem is that there is a major panel overlap seam in the way, forward of the inner seat belt mount, rearward of the stock rear cross member/seat support. Had to break out the large dead blow to reshape that.


After the "gentle" mallet work


Beating administered. Cleanup & paint to come, on the underside also. Edit - that is glue on the inner forward seat  cross member , not Rust!


Now the seat can be made level without lifting the sill side


Side note - I guess Nissan wanted to build in the rusting process that was mostly resolved on the outside (compared to classic Z's anyway


Seat cushion controls clear the sill


Inside clearance matches the pas side


Slight problem in that the rail spacing is not even left to right - I have to make a wider rail conversion for this side. Fortunately a 2" "U" channel will take up the gap.


I don't want to simply cut & offset the bolt down points relative to the rail.



 Started on the wider inner seat rail . Need to weld it up, however the basic element is ready to move forward



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Got back from Baltimore yesterday afternoon, so back on the seat install today. Had to do some more pounding on the tunnel.  Metal only stretched so far, then it split, about 3" wide, a couple inches above the seat crossmember.


flange tore where the black paint is on the tunnel.


dynamat after paint


after that, I welded the rail adaptors - tacked in place, then removed to stitch  






plug for stock seat belt bolt hole


seat belt outer


seat belt inner , also added snaps in the carpet for the leather handbrake cover


Driver's side, rear attachment


sill spacing - just clears the seat belt


Seat will be re-upholstered, just not today


pass seat out to install cushion, harness routing




Headrest cushions have to be stripped to fit the new leather covers, the original covers are glued to the foam



added the support bracket with two nuts to the driver's side of the  strut brace. Have to do the pass side tomorrow, ran out of daylight






Edited by HusseinHolland
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Added the pass side belt reel retainer. I;m going to make a padded cover for the brace



Daytime pic with headrest. New leather for the seats has the same green stitching. I also went with a dark grey inset for the perforated panels. Not sure it's dark enough though. Seems more like a medium grey to me. Pics later



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