71 is said to be the best, if your going to look for one better in a dual plane go for the rpm air gap, the performer I'm guessing would be worse than the stock 71. Here is a 71 340 intake that i gasket port matched, milled the plenum divider, and did a lot of plenum massaging! Then you need to run one of the 71 t-quad's !! to bad i probably wont run any of this for a long time i like the 6 pack on my 340 right now!