The higher the lobe seperation number, the better the vacuum signal, the broader the powerband, and the better the idle quality. The second most important number to look for is the lobe seperation, which is the distance in degrees, as measured on the cam, between the point of peak lift on the intake lobe and the peak lift on the exhaust lobe. 050 number is, the longer the valve will be off the seat (hence the term duration), which will affect vacuum. 050 on a TBI will cause the MAP sensor to go nuts because the MAP wants to keep the vacuum within a certain range (which if I remember correctly is 17-19 inches). The LT1 cam is also a good choice as well.įor a TBI application, the number to be the most concerned with is the duration. 050 is good (206/212) and the lobe seperation (112) is also good. I think the 12-249-4 is better cam between the two you listed.
