I guess the FBS heads for mopar was an attempt to get more market for the design, as they were already available as AMC versions. There is only so much you can do with an inline wedge design with the regular siamesed intake ports. Actually the AMC heads are still available as billet heads. I really don't know much about them, but guess they are an upgrade over the 18 year old 440-1's currently on the block. But we'll see, once I get them here I will take them to a local flowbench, and I have some other data from the same bench to compare with, our 440-1's, several B1's both regular and MC, and CNC'd MW Victors.