Bob, the one I just posted is designed for low riser and medium riser heads, on my #13001 intake adapter. It will also fit directly on a 351C with stock heads, although you would have to use one of those pans over the valley, since there is no bottom on the intake. So, I can now do these billet intakes for any FE (LR, MR, HR, or Tunnel Port) except the SOHC, and I do plan to do an SOHC version in the near future. As a guess I would say that the billet intake is probably 10-12 pounds heavier than a sheet metal intake.
Keith I would do a top like that for a pair of Dominators if I get an order for one. It would take me a little extra time because the design and CNC code would have to be modified, of course, but it wouldn't be a big deal to do that.