ZRX seat on a '77 KZ650C?

Hey all, I've heard around the grapevine that the foam and cover from a ZRX will fit with little or no modification on a 77 kz650 seat pan. Is this true? If so, will foam and cover from this seat work?

cgi.ebay.com/ebaymotors/Kawasaki-ZRX-120...ce9970#ht_3481wt_870