If you are only looking for little gains as in the gain of torque between the Performer RPM intake vs the Performer intake at lower rpms, you might try advancing the cam a few degrees. This will achieve the same results.

Find out which cam you have and if it has advance ground into it. Comp cams come with 4 degrees from the factory. Edelbrock may have 5. You advance the cam timing to gain bottom end torque. I have played with as much as 8 degrees advance, it worked great.