I tried a different search and came up wit oil filter information. Some have more restriction than others according to the thread. I am going to try a different filter then a lower weight oil just to see if there is a difference. I like plenty of pressure but dont want to hurt the distrbutor shaft or any thing else.
I'm betting you have a Mellings HP pump and not what is quoted. Do you have the p/n for the pump? If it is a HP pump that will explain the pressure. Changing oil weight/filter will have a little effect, but won't help w/as much pressure as you are running IMO.
Either way, it is too much pressure, as was stated by rbohm, 10psi per 1000rpm is the general rule of thumb. Too much pressure is only going to hurt the internals... unless you have the need for a HV pump?!
I run Mobil 1, 10w30 in my 65 289. It's has always been 80 at cold idle. It drops to around 35 at hot idle and 50-60 at 3000 rpm. That is typical for the 289.