
Collectorbox is different as is exhaust can.
NC24 has a high level exhaust

Collector boxes do fit both engines but are different, as far as im aware there is no link pipe to convert the nc21 to a high level system, what you can do is use an aftermarket nc24 link pipe and cut the collectorbox up, or cut the link pipe to bodge it.
Heres a lovely picture of RCV4's stainless steel copy.

Here is an image of the NC21 box.
