Intake Manifold Dilemna

If it's the 71 manifold, with the last three of the casting number being 100, you have the best TQ manifold Mopar made. So the stock eliminator guys tell me. The high compression, Thermoquad 340 (71 only) was rated 10-20 hp higher by the NHRA than even the 68-70 motors. Food for thought.
I don't know how the flow numbers stack up against a large port performer, though. The performer is as far as I know the only aftermarket 4 barrel that has the offset water neck, important if you are going to use the late model aluminum small air conditioning compressor, or are putting the motor in a newer vehicle.
I hope this helps,
Alan