Oregon Cam provides a detailed cam spec right off the grinding machine.To simplify a bit it's an their 818 grind,211 degrees duration at .050 lift,total lift at valve based on a 1.47 rocker ratio is .422.Lobe separation is 110 degrees. Duration at .006 is 276 degrees,generally this might be called "advertised duration".The cam dialed in on the numbers but I used a SBC offset key to advance it two degrees.
In this 261 with zero deck Ross flat top pistons,9-1 compression,a 350 CFM Rochester 2G carb on a modified stock intake,initial timing set at 10 degrees with a total of 36 degrees.....the engine idles smooth at 700 rpm ,the valve action is no nosier than stock.Feels real good through the gears in the 50 Chevy truck.Just a few brief test rides because of nasty winter weather.
On the exhaust sound,single exhaust inline 6's always sound like a UPS truck.
