My '67 Plymouth Fury has the original 318 engine which has wear but runs very well. No lifter noise and is peppy. I had not run it for three days and this morning when I started it the oil light stayed on and I had lifter noise. I turned it off and checked the oil which was down not quite a quart. I started it again and the light still remained on but the lifter noise was less. I was about to turn it off again and the light went out and the engine sounded quiet and normal. Last night the outside temperture was in the low twenties and I am running Valvoline VR1 20/50 oil. I am going to change to Valvoline VR1 10/30 and see how it behaves.
I am thinking that the pickup tube screen may be partially plugged up. If I do change this I should probably change the oil pump also. Can I still get a new pickup tube and screen for this engine? Also, do you need to remove the rear main bearing cap to change the oil pump on this engine? Thanks very much for any info here.
John

There's no need to replace the pickup tube.Just clean it.It's not unusual to find pieces of the valve stem seals stuck in the pickup screen. If you do drop the pan, you might as well change the pump while you are there.

20/50 oil at that temp will take a few seconds to pick up and get oil pressure to the lifters. If you don't believe me try to pour it out of the bottle at that temp. It will be like stiff molasas. The bottom will be the first to get oil. Put some lighter oil in at these temperatures. Don't go looking for trouble. In real cold it will even take a few seconds for 10/30 to pick up. I don't call 20 degrees real cold though for 10/30. I am talking -10 and colder.

I have run 10w40 in all my vehicles except my newer 98 Ram and 04 Expedition. Have for years w/o a problem. Winter and summer. In Nebraska, temp ranges from 80s, 90s even 100s in the summer to 20s to as low as -20° or lower in the winter. Never changed the grade of oil to match the season. One vehicle in particular that I had the longest, my 74 Power Wagon 318 2bbl/727, had well over 275,000 miles on it and didn't burn a drop when I finally let it go. (Leaked a little, but thats a different matter ) I just have never understood changing grades twice a year

Thanks guys for the tips. I will change both of my Furys to the 10/30 VR1 Valvoline for now. I was in the Stop & Shop and they sell their own brand of oil and also Citgo. Both of the 10/40 oils had the SL rating and not the SM. I am going to see if they would be suitable for both of my 318 engines to use. Thanks again.
John

Well broke in engines with standard valve springs and cams I wouldn't worry about the 10/30 oil in them. If you are add a supplement. Citgo is a good oil.