[601HP]

Here's another approach to your question regarding worth, value, investment...

Contact any of the experienced FE engine builders. Ask the cost of building a 428 and a 427. Each engine would be considered a street engine with hp in the vicinity of 450-460. Similar heads, valve train configuration, intake.

If you find a builder for the 427 whose sale price isn't $3k to $5k costlier than the 428, I'll be a bit surprised.

David