The subject of S13/S14 gearbox swaps into S30’s is pretty much old hat now and covered quite well in other threads. However, I thought I would share my experience of doing the same thing but on a 280ZX 2 str Coupe. I replaced my faulty manual gearbox, after attempting to repair it and failing, with a low mileage S14a box. The first thing to notice when compering the two gearboxes is the length, the S14 gearbox is a lot longer and the need for shortening propshafts etc. is a given. Other things such as the gearbox mounting adjustments and internal trim are less well documented, so that what I wanted to share. Old and new boxes: The machining necessary to the bell housing of the original gearbox is covered nicely here: http://zhome.com/ZCMnL/tech/240SX5spd/transmission.htm A local firm undertook mine as a favour to my father-in-law. The box was given a good clean and inspection before bolting it up to it newly machined bell housing. The speedo drive needs to be swapped out with the original. The one from my 280ZX had the blue drive pinion with 18 teeth; luckily this matched the one from the S14a box. However, because the 280ZX drive is slightly offset it had to be rotated 180 degrees for it to engage the drive in the gearbox itself. Because of this a new locating slot needed to be cut into the speedo drive body with a small file. The rear gearbox cross member needed to be altered as the position of the mounting is now about 2” further back to the original position. To achieve this, I cut out the centre section of the cross member and welded it back together as pictured. I used 5mm thick steel bar to reinforce the assembly, welded across the bush holders. I also added additional fillets welded across the cut surfaces to reinforce the box sections. Cross member: To get the correct position of all the pieces I had the gearbox bolted to the engine and supported by a jack. I bolted all the individual pieces onto the body mounts and gearbox mounting points and tack welded them in situ. The final welding was then done on the bench. Welded Cross member: When fitting the gearbox to make the mounting bracket, I did not have the shifter installed in the box and it all fitted perfectly. When I fitted the shifter assembly after welding up the cross member, things did not work so well. I used a B&M short shifter and the top of the shifter assemble where the gearstick slots in fouled the transmission tunnel. This would not allow the gearbox to be fully raised to locate the mounting bolts on the cross member. The transmission tunnel requires to be trimmed back to allow this clearance; I removed about an inch of material as in the picture below. Tunnel fitting before and after: The prop shaft again is something that is well documented, however the way to measure the correct length is not so well documented and I got that wrong. I measured from the flange on the differential to the rear seal on the gearbox. When discussing it with the company I used in Bristol it turns out I had measured it incorrectly. The company kindly lent me the front part of a propshaft (the bit that goes into the gearbox) and instructions to "stick into the box as far as it will go and measure from the middle of the joint to the dif flange". For my car that length was 576mm. The prop needed 52mm taking out of it to fit the new box. With all the mechanical bits done the interior needed to be sorted. Fortunately most of the interior console bits can be reused. The trim around the gear stick has a plastic coin tray as part of the centre console. With the new position of the gear stick this will no longer fit. The answer is to turn it around 180 degrees so the coin tray now sits under the ashtray. However, the mounting holes that are used to screw this piece into the console itself will not line up to allow this. They need to be clipped off the plastic, a large washer can be used with the screw to hold the trim piece in place see picture below. Coin tray: Next issue is the inner gearshift boot seal, again it cannot be reused in it original position. To fix this it can be rotated 180 degrees and it works quite well. However, the metal clamp which screws to the tunnel to hold the rubber in place needs to be moved about an inch and a half backwards. This will require the holes to be re-drilled in the tunnel to suite. Finally the gear stick gaiter can also be reused by again turning it 180 degrees. I did try a leather gaiter, but it did not look right and I actually prefer the retro 70’s rubber bellows – personal choice. The only part that could not be reused was the gear knob as the thread is 10x1.25mm on the new gearstick. Which is a pity as I rather liked the old one. Working on the car I could only raise the car up on wheel ramps. So I did find it a struggle to do due the box swap mainly to the space constraints. The whole conversion itself however, is pretty straightforward to do. Having driven the car, only up and down the road a bit to see if it works, I would say the car feels much better. Looking forward to giving it a full road test in due course.