This larger bore flange is for the 2.50' exhaust pipe size. These flanges are not oversized units our competitors sell. Oversized flanges will cause clearance problems with starters ets. These sre the strongest fittings in the market. Some of our competitors provide easy -to-break aluminum flanges in the name of "cost reduction". Photo shown is of a bare casting. Silver or Gray Ceramic coating is also avaiable at additional cost.
Application :This 2-bolt flange is used on the Round Port header Left Hand manifold for the 64-67 GTO