Bowhay I had a flat top piston 406 with world products sportsman heads(200cc intake ports) I used a comp cams hydraulic it was .507 lift or .501 can't remember and advertised duration was 292 I think. Dur@ .050 was around 244. Actually, I think they call it a MAGNUM 292 ...I started with the Magnum 305 and it was too much and went to the next one down and it worked beautifully. My compression was around 11 to 1 I ran a performer RPM and a 700 DP . With a 10 inch converter and a 4.10 gear in a 3700 lb Chevelle it would 60 ft 1.71 with the ft break. Ran 8.17 in the eighth.Not a rocket ship but would really set you in the seat for a big heavy car. That motor is still in that Chevelle today but I haven't ran it in years since I have my BB Nova.