Collector/Header Muffler Gaskets. Collector/Header Muffler Gaskets; Triangle; 3 Bolt Holes; 2.5 in. Dia.; 3.5 in. Bolt Circle; 3/8 in. Bolt Hole; Bulk Perforated;. Now an important part of Holley Performance, Mr. Gasket continues to expand application coverage with more and more new products for race cars and muscle cars alike.
