i have an 88 civic hatch and i'm putting a 5th gen civic dx motor in it. The only thing is, i have another 4th gen civic tranny laying aorund, and it won't fit up to the 20-spline 5th gen clutch( on the motor still). But the tranny sitting around is 21 splines. Are all 90-91 civic trannies 21 splines, and 88-89 tranniesonly 20 splines? I've been trying to figure out what this 21-spline tranny is. It's an L3, but i think it's an si tranny. Is there any way to tell? Because i have a 88 dx civic hatch, AND a 88 base model, and they are L3's too. Thanks for any help!

 

wow.. this topic goes way back for me. The 88 trannys, axles and hubs were 20 spline. The 89-91 were all 21 spline. HTH