Chevrolet: engine building, roller lifters, hedders

Question
I rebuilt a 454 Chevy using all new components except the block. The block was cut 30 over. When I started it , the motor smoked and I noticed a puddle of oil by the collector on both hedders. There are all new rings that were installed correctly, the heads are brand new Canfield Aluminum. All new pistons, cam, roller lifters, intake etc. Basically everything is new. What is causing the oil to come out of the exhaust ? Please help with any suggestions. Thanks.

Answer
Were the cylinders properly honed before the pistons were installed? Did you index and properly install the new rings on the pistons? Were the pistons correctly fitted to the cylinders? There are alot of things that could have been done wrong. If every thing was done right, it could just be that the rings are not seated in yet.