This is the description from Summit Racing-
Header Collectors, Steel, Weld-On, 2 in. Primary Tube Diameter, 3.50 in. Collector Diameter.
These Collectors received positive reviews on the biggest racer forums- Yellow Bullet, ETC for years, but production has been discontinued.Specs for these Collectors are on Summit Racing under the FlowmasterPart#. New Collectors are merge style, costing 3-4 times more.
Here is a New Old Stock pair of 4-2-1 collectors that scavenge exhaust to increase the next intake charge- adding power budget friendly
