1968-1974 Chevy/GMC BBC Truck Headers. These long tube headers are designed to fit 1968-1974 2wd and 4wd Chevy Trucks, Suburbans, Blazers and Jimmy's with Big Block Chevy. They feature a black finish with 1-3/4" tubes, 3/8" flanges and 3" collectors. Headers include gaskets, collectors and bolts. Must modify exhaust to retain factory catalytic converters. May require clutch linkage modification.