[Geoff]

There is no right or wrong rocker geometry. The narrow-est mark in the centre of the valve tip is very popular but it takes no account of what is happening on the prod side. What happens on the valve side in terms of lift & area under the curve ...... is times one. On the prod side it is times 1.5 [ for a 1.5 rocker ]. David Vizard's BB Chev book has a chart of various rockers he tested. Lift at TDC & max lift was tested as well as the overall ratio. The numbers are all over the place & show you can spend a lot of time to gain nothing except a warm & fuzzy feeling.