Well this is JMO. My 416 has Wiseco pistons zero deck hgt. 72cc W2's. CR is 11.2. I believe that the 528 cam is around 254*@.050, This should work real good in a 408. The long stroke eats up alot of duration. How loose will the converter be? That intake will work very well with those heads. On my old 340 that manifold was faster the either a Holley street dom or the strip dom. The carb is good until you get some good heads. Then they really like a 950HP. I would use at least 1 3/4" tube headers as well. You will like the TQ they make. Jim