I was going to try the Edelbrock performer RPM 2-0 on the 502 with my merlin oval port heads this year and was wondering if there would be any gains in spending more and running the Merlin dual plane manifold.Thanks James

I have the performer air-gap on my 502 with merlin oval ports, has run fine for me. I havent seen any flow numbers however they are both supposed to be good manifolds, I doubt one would be any noticeably different than the other with performance.

I had really good results with the Weiand Stealth on a similar package.