Several Brands of Headers are Available for the 240SX Including:
EGR inlet on the headers didn't line up well with the EGR pipe running from behind the engine. Had to extend the o2 sensor wire. The steering bolt scraps the headers causing car to "catch" briefly. Irritating, but you can notice a reasonable power gain.
The Greddy header is a 4-1 short header design that bolts to a secondary "downpipe" that ends at the location of the stock cat. These headers are prone to cracking, welds giving up around the collector and the flange on the head. These headers are very loud.