One example: The Z/28 uses unique 4-2-1 headers. "Camaro Z/28 Exhaust Manifolds – This kit includes dual, hydroformed “tri-Y” headers from the 7.0L LS7 engine, offering increased airflow for other LS-series V8 engines." I wonder if this fits on LS1 too?

Z/28 Parts Packages Coming for 5th Gen Camaros - LSXTV

Chevy Performance: High Performance Racing Parts | Chevrolet