Hi DocDirk,
Another aspect is the hood scoop height. I know the Torker is the shortest manifold currently available and that it works fine (with bungs) as an EFI unit.
If you go with any other manifold you may need to make the scoop quite tall. Voice of experience!
Also, most folks don't seem to use a large enough air filter. Check how many square inches you need and then go looking at air filters. You may have a bit of a surprise, particularly with a big engine. Big airflow requires a pretty big filter. Exhaust systems can eat horsepower, but so can air filters that are too tiny
I agree with Byron that there won't be much difference in the manifold's effect on performance.
I had to enlarge my scoop (see my Gallery), dunno about West Coast.
Hope this helps,
Tom