They are flame cut from .375" steel plate and are ready for your imagination to run wild in building a set of custom pipes. Ports measure 2.750" x 2.250" and are oval port.
Header flanges should fit most BAE, AJ, Indy, Dart, MJBE, Keith Black, Veney and most other fuel type cylinder heads.
RBS carries a full line of copper exhaust gaskets to compliment your bitchin new pipes.