My 440/493 is a 440Source 4.15 stroker kit. I use their pistons and rods also. My 63 is a street car that I only race about once a year lately but this eng has been in my car since 2011 and I have raced it about 7 times since then. Shift at 6200 and trap at 6400. Has run 10.70's driven to track and raced as I drive it. Its still going strong and running great. Ron