I was wondering if anyone knew the standard exhaust port size for a 454 BBC. They are stock iron heads with round ports not square. I'm at work ordering parts (I know, 'working hard, or hardly working') so I can't measure them real quick, but the parts place has gaskets for 2.250 and 1.810 inch ports. I was hoping to order them today before I went home so they would be here for wrenching over the weekend, but if there is no 'standard' port size I might have to wait to order them until after I go home to measure. Any ideas?