Haden

I think i have puzzled it out. I found info online stating that the sr20 and rb20 det shared same back side of gearbox and just had different bellhousing so I assumed I could swap a rb20det bellhousing onto my gearbox and it would be same as rb20det gearbox but it looks like the tail side is different too and the rb20 tailside is shorter by just over an inch which would explain my issues. Will buy a rb20det box and go from there

Hello, Im currently part way through a rb25det neo swap into my S15 silvia. Car was factory sr20de auto but was manual converted previously. I am using r33 front subframe and engine mounts and am using the stock sr20de gearbox with a rb20de bellhousing to make the box the same as a factory rb20det small box. My issue is the gearbox is sitting around 1.5inchs further back than factory location so the mount doesnt fit and the driveshaft is too long. Everything I read online said using this small box means I can retain factory driveshaft without mods. Was this wrong? Is there a different crossmember I could use? How can I use factory driveshaft?? Thanks