Canton - Valve Covers Small Block Chevy Centerbolt Fab Alum With Fill & PCVThese SBC tall fabricated aluminum valve covers come with pvc port holes on each cover and a fill bung with billet cap on the front of one cover. The valve covers are designed to be light weight, yet strong enough to prevent warpage. They are constructed from . 100" aluminum, with heavy wall mounting tubes and are welded while mounted on cylinder heads to ensure a proper fit. Additional fill bungs, AN fittings, or breather stacks can be installed on a