Yeah, a '88 flywheel and clutch is compatible with an '88 transmission only. But that's okay. Basically you can't stick a '91 motor onto an '88 trans without buying some extra parts. But you can leave your '88 engine bolted to your '88 trans and you would never know.
The splines in the differential of the '88-91 transmission are the same as they are within the first gen trans, so your stock axles will slip right in.

By Justin (207.102.0.6) on Wednesday, October 01, 2003 - 11:13 am:

The input shaft is in transmission, it is only a reference for the clutch, the axle spline is something completely different

By jms (198.26.123.36) on Wednesday, October 01, 2003 - 09:00 am:

so dont the axels have to have the same spline count?

By jms (198.26.123.36) on Wednesday, October 01, 2003 - 08:59 am:

the crx domain website says this:

88 manual transmissions have an input shaft with 21 slines

89-91's have a 20 spline shaft

By Justin (24.69.255.203) on Wednesday, October 01, 2003 - 08:28 am:

The spline count is on the flywheel, if you have the complete set-up, your set I don't remember the axle count but it's the same for all of the civic's up to '95 (D series single cams)

By jms (198.26.123.37) on Wednesday, October 01, 2003 - 06:32 am:

So what about the 88 trans? I can get a complete motor trans ECU and harness out of a crashed 100,000 88 CRX Si for only $350, with AC too. So because of the spline difference will I need to change out the flywheel or...

btw how many splines do the 1st gen axles have I didnt count them yet.

By Tim (4.7.217.104) on Tuesday, September 30, 2003 - 07:55 pm:

The ZC is a DOHC d16, so it is not related to the B16 at all. Stick with something from the d16 family. As for the number of splines on the transmission I don't remember. The change came between 1988 and 1989 models, the later being the more desirable one. You can use any 1989-1991 transmission from a CRX or Civic.
Don't use the transmission that comes with a JDM ZC because it requires equal length driveshafts and therefore you will need to get a set custom made. Just use the '89-91 Civic/CRX transmission and your stock axles will slip right in if you have positioned the transmission properly from side to side. I installed the axles before I welded in the engine mounts so I was sure the engine was in the right spot.

By jms (198.26.123.37) on Tuesday, September 30, 2003 - 02:42 pm:

Justin, Darren, Jared T. feel free to input your expertise...

First does anyone have any links for the popular JDM swaps or any clubs online at all?

Second check out this one, a nice concept CRX
http://www.thecrxdomain.com/

Third I am in the process of clearancing my engine bay for a CRX/Civic Si motor. The above link shows differences with the motors that confuse me. I thought the JDM ZC and B16a1 were the same? Ill probablly go with a USDM D16a6 but I want the most power for the least amount of welding/cutting. Also some trans questions, some of the 88-91 have 20 splines some have 21 so what works with all stock components?