Big Block Chevy Sonny's 5.3" Semi-Hemi Bore Space Stainless Header Flange

Precision laser cut form 3/8" thick 304 Stainless Steel, our header flanges are manufactured in the U.S. and are machine surfaced. These header flanges are specifically made for 5.3" Bore space Sonny's Semi-Hemi Heads.

Port Size: 2.502"

We carry over 450 different header flange designs, so if you don't see the flange you're looking for, talk with one our tech reps about custom header flange cutting.

Flanges sold separately.