I think you should try changing the vacuum secondary springs on the carb. The silver spring that the 1850's come with is pretty stiff, and doesn't let all four barrels open as soon as most people want them to. Here is a link to the jegs site that sells the spring kits.
For $10.00 it's worth trying out. Go to the lightest spring in the pack, and work your way back from there. Listen to the carb as the engine revs to make sure the secondaries are opening up at about 3000 - 3500 RPM's. That should give you the best all around performance.