[MrPbody]

My point about craters has nothing to do with the parts. Although they do use stockish stuff, as opposed to Merlins and Eagle craters, which use high-end racing stuff. The point is, they are NOT what they're cracked up to be, just like anything else in life, where advertising hype and convenience take control. A "custom" built BBC will stomp a factory engine, IF your engine builder is any good. And usually at the same or lower price.

If your 454 was converted to "internal balance", be certain the balancer and flexplate (or flywheel, if a manual) are 427 parts (or 396...). If you're using 454 parts, they are the issue. These are easy to identify by the weight "added" to them. The balancer has a large "chunk" of metal cast in to one side. The flexplate has a weight welded to it. A manual flywheel will have a series of holes drilled into one side. If any of these situations exist, you have a mis-matched set of stuff.