Hey Dave I just did a check on the 408 Roller cam and come up with 8 degrees of valve overlap. How does that compare with your cam? Also I compared my Magnum heads to some 302's and they looked very similar to me in terms of runner size.(Although I may be confusing the 302's with my 273 heads) I'm hoping that 408 cubes trying to breathe through the little ports I should have very good port velocities. Of course I won't know until I get this heap running. It's all bench racing at this stage

Oops!! I goofed, the overlap on my cam is 41 degrees. Not 8. I used the .050 duration figures and was supposed to use the advertised number