Rebuilt 318 Refuses to Start

Rusty,
I have a full MSD ignition. Box + distributor. You are correct in that it is a magnum block. The flooding is questionable though and is something that we can't really pin down. The carburetor was full of gas, but when I pulled the #1 plug, it was bone dry. None of the plugs have been wet throughout this process, ever. I just got finished cleaning the plugs off just to be sure now. They had a little carbon on them from before when I was driving the vehicle. This engine has timing marks on the timing cover. The block was decked for sure, and I think I had the heads milled just a tad to clean them up. All of this work has been done correctly by a reputable machine shop and was installed previous without any problems.