hello, as you might already know, i built a 302 bored .060 with a mellings high volume oil pump about one year ago.it is now in an 89 mustang with a 5 speed.now i have 10w30 in it but have been told that the oil i have is too thin for my needs. it idles at about 65 psi when coldand gets to about 80 psi when revved.but now summer is here in texas and ihave noticed when warm, the psi would be at 30 at idle and 60 when revved. sometimes when driven longer it gets to almost 0 psi at idle. there is no metal shavings in the oil andit is at the right fill level. i am thinking it is just the thin oil. i want to put castrol 10w50 in it or maybesome sort of 10w40. what would be the best route to goand what do you think the low psi is being caused from. the motor does not knock or tick at all. i am using a mechanical oil gauge too. i don't really know the mileage on this engine but it can't be more than 1500 miles old as this is just my project and not my daily driver. sorry about the lack of using the spacebar. i was on a different pc and the keyboard wat sticking or something.