Retrofitting 2000 radio into a 98

I have a 98 TS and I aquired a "WB Package complet with radio and all trim and wiring. I have a non RDS radio with the 21 pin main and 9 pin aux connector. The new radio has the 24 pin main and 12 pin aux plug installed. On the harness it is missing the radio plug from the donor vehicle.

I just dropped the van around a 2004 3.4L engine and planned to update the intereior a little bit. Is it possible to make this work?

I just spotted your posting ...I am doing the same thing Installing a 2001 Monsoon radio in my 1997 Trans Sport ...I found the connector with 24 pins on Ebay ( EBAY Item # 5826933643 ) you can search for the item # and it will come up ... Bob in MICHIGAN