Have a 1965 292ci and recently changed oil (went from 30wgt to 10-30) and noticed slight change in pressure, use ta' idle at 30psi and now is at 25. Also oil filter is shorter than what use ta' puttin' in (Napa says I'm good). Would these changes cause pressure ta' drop? Am sure I'm O.K., but would like second opinions. Pre-thanks in order.
