My 305 tpi has 206k miles on it. No ring smoke, rich under acceleration, little bit of valve quide smoke after sitting. I know the end is near because the oil pressure drops dangerously low after the engine warms up at idle (less than 10 psi). Oil pressure is about 45 when I first start it, then drops off. Does anyone have a suggestion about what oil to use. I am using 10w30 pennzoil now, have used the valvoline extended life stuff before. Any other suggestions other than a rebuild. I'm trying to save enough to do a 383 swap.

 

You might try a straight 30 weight or a 20-50. If you're not leaking or burning oil, I'd switch to synthetic to make sure you've got protection incase of very low pressure.