[rustyBob]

I just can't see Offy makeing a manifold that didn't come close to port matching a set of heads it was made to fit.........I have an Offy intake that is a port-a-sonic dual port single 4bbl intake from back in the 70's that is basically 2 single plane manifolds in one there is a set of runners for the primaries and a set for the secondaries, its hard to explaine this thing but there is a devider in the runners that seperates the primaries from the secondaries its the only manifold that i have ever seen like it and man does this thing look odd it's very short in height kind of like a stock 4bbl manifold but the ports matched up rather well i only had to do a little work to get it to match the ports on the heads. Maybe some body at Offy can give you some info on your manifold that will help.