Posted by Vaughn on Thursday, November 23, 2006 at 12:33PM :
In Reply to: cam spec question posted by mclark on Wednesday, November 22, 2006 at 10:50PM :
Lift is how far the valve will open I believe in thousants
Intake opens at 50 degrees BTDC and exhaust closes 50 degrees ATDC
180 is the overlap duration between In/Ex valves between opening/closing
In 265 is the total degrees between the time the In opens/closes. Same is applied to the Ex valve.
Now that you have a complete understanding of valve timing, to answer your question - Yes. The longer the valve duration, the better the engine breaths. Exceleration and high end performance is the gain, but poor idling/fuel economy is the loss.
I would look for a torque cam (short durations in degrees). It will allow great engine lugging off road, high torque for excelerating with loads and good fuel economy in a truck that has 5.83 gears.