It's a 305, same block but I haven't had this problem in over 4 years. Just started last night. At idle or even at 2 grand no problem but since I don't have a lift(guess I'll have to take it to a shop) and even thin me can't fit under it. Have ramps and I'll put those under the front and jacks under the back so the wheels are off and set my throttle for high speeds and see if I can find the leak. Not much back left to mess around under a car.