your very welcome, just piping in, as i have been gone for a few days.
mr stew,
i also think you will want full boost before 4K rpm. mine starts building boost visably around 2200 rpm. 8-10 psi @ 3200 and max's at 11-12 now. i am not quite sure of the rpm range for the 181 even with a bigger cam. do they have harmonic problems like a big stroked 6 does. that may also limit your rpm's it does for me. tom
