Port-o-sonic or Holley Street Dominator?

FWIW, it's my understanding that the Port-O-Sonic is more of a performance intake (i.e., works better at higher rpm) than the Streetmaster. I think I remember that back in the nineties, Ed Hamburger recommended the Port-O-Sonic as one of the best performing SBM intakes available.

Edit, just noticed that the OP referred to the Streetmaster as a Holley intake. As Rumblefish notes, the Streetmaster is an Edelbrock intake. The big block Holley Street Dominator is supposed to be really good, but the small block Street Dominator, as I remember from the one that came into my possession a while back for some reason, has 318 sized runners.

I did run a Port-O-Sonic on my stepson's 340 Duster that had a fairly mild cam. Worked well, I thought.