I am in the process of building a 400 EFI SB and trying to figure out what cam to use. This will be street and occasional strip driven so I want good street manners, good vacuum and low end torgue. I also want to try to pass emmissions sniff test (IL doesn't check under hood for CARB #'s). Is anybody using this cam in a 383 or 400, and what kind of vacuum is it pulling and how much hp are you making, are you happy with it. I would like to make between 400 and 450 hp. I haven't got the heads yet but thinkng about GM Fast Burn because I want a good combustion chamber design which should aid in better emmissions. Somewhere I heard they are in the process of revamping the ports because they weren't happy that they were out flowed by most aftermarket heads, so I am waiting to see what they do before I buy them. Does anyone use Fast burn Heads? I plan on using a miniram intake, I figure the 400's torque will make up for any low end torque lost by the stock TPI. Bottm end is Scat cast crank, Scat 4340 5.7" rods, KB Hypereutectic pistons with 9.5-10 compression. Any comments?