Description 20v 4age – Exhaust flange Exhaust flange to suit a 4age 20V. Available in mild steel or 304 grade stainless. Specifications Hole dimensions: The main holes in these flanges are cut to match the same diameter as what the original exhaust ports are which is 31mm for the Silvertop and 34mm for the Blacktop. As such the pipes are intended to be welded directly to the outer face of the flange instead of first fitting into the flange holes and then being welded. However due to the outer profiles being the same it is possible to use a Blacktop flange on a Silvertop head and then make use of the larger hole openings in the flange. UPDATE: ALL OF THE STAINLESS STEEL FLANGES NOW FEATURE 35MM HOLE DIAMETERS. Supplied finish: These flanges are supplied in a rough laser cut form. As such finishing / flattening work is likely to be required before being used.
