performer RPM air gap v.s ported LD4B

Yup. However, I think they may have eliminated one. I was just surfinga round...I can see the small port Performer, p/n 2176 (non EGR) and p/n3176 (EGR), both are listed as "318/360" with the smaller ports. No other larger port Performers are listed. The next step up is the RPM. That has the larger 340/360 sized ports. So I'm thinking they may have streamlined things. But I'm sure I've had small and big port Performers in my possesion at the same time...lol. I do know the port castings were identical, they just machined them to the larger port size. I havent bought one in a while.