I am working on a similar swap right now (96 vtec into 89 Si). There is only one mount actually bolted to the motor, you will reuse the Si mount, it bolts right up but you have to trim the plastic timing belt cover. No aftermarket mounts are needed.

Use the Si Clutch and flywheel!!!! I mixed 89 and 96 parts and as a result I cant get the clutch to engage and have to pull it all back out.

I am not worring about the vtec on my swap right now but I was told the easiest way to do this is to swap everything from the Si block to the Vtec block (intake, distributor, exahst, sensors, etc) and then buy a ZDYNE computer that has been configured for this swap. Supposedly it plugs right in to the Si harness like the stock ECU but the fuel has been remapped like the Vtec ECU and it has the wire output that is used to trigger the Vtec. We will probably get this ECU for our swap later.

I was told that the later (92-00) exhaust manifold and down pipe were the wrong length but it bolted up in my swap just fine. I am unsure of the 92-95 unit but the 96 is a 4 to 2 to 1 type header which is better than the Si header.

I currently used the Si intake manifold but the 96 manifold has longer runners which gives more torque (very needed in Hondas). Supposedly I can swap all the sensors and the fuel rail from the Si to the 96 Vtec intake. I am gonna try it when I pull the motor back out.

I hope this helps you out a little