If you build the engine right in the beginning and take reasonable care of it, it should easily last 100K miles. Some stroker engines - especially older ones - do tend to burn a bit of
oil because of the piston design. If your 427 is built on a stock block, then then it's probably the nature of the build. Rebuilding it probably won't change anything.
I drive my car about 5-6K miles a year. Give or take.