The 4.6L engines were designed for 5w-30 as stated by 69 GTX I would stay with 5W30 Synthetic. I like soups oils. QSUD - Pennzoil.
0W-30, 5W-30 or even 10W-30; take your pick. If you do any heavy towing or use it in severe operating conditions, skip the ILSAC oils all together and go with a 10W-30 or even 15W-40 HDEO in mineral form, or a synthetic variant.
You might try a 40 and see if the lifter tick goes away. Just for funsies.So I know I asked this question years ago. I am coming back to this post to update what has gone on. The engine is still performing marvelously. I have no complaints at all. I have used both 5w20 and 5w30 over the last few years. The engine just doesn't care. I don't do long oil intervals. I use have used a lot of different brands of filters. I have decided to stick with Motorcraft this last year. Perhaps it tears but I don't leave oil in long enough to worry about the stresses that may bring that on. I have had many different brands of oil in the engine. It just doesn't seem to care what's in it. I have a slight tick when idling in gear and stopped but nothing distressing. ST, Motorcraft, NAPA, Chevron, Castrol, Quacker, and Pennzoil all seem to run fine in the engine. Right now I'm running Castrol GTX ultra clean 5w30 in it. I could run a full synth but I just don't leave oil in the engine as long as it could possibly go.
The vehicle is my work horse. Literally. I use it to do my satellite installation jobs. I have a ladder rack on it and carry around two extension ladders and a 8 fool folding ladder. I am retired and this vehicle brings on a good check for play money and those bills that creep up on you out of nowhere. By that I mean a new appliance that needs fixed or replaced.
So like I said I bring this back only to let someone who may want to know how it went so far. I expect this truck to last me a very long time unless something comes along and crashes into it. Good luck with your engine.
Sound's like you changed the oil a lot! How many miles on it now? Must be over 30,000!Thanks for the nice replies. The reason I asked originally was my concern that the clearances on a rebuilt engine might require 5w30. I gather that may not be the case at all. I do have some left over 5w20 oil which I will use with confidence now and not worry I am doing some unknown harm using to light a oil on the rebuilt. Meanwhile I can decide if I want to move to 5w30 or just stay with 5w20 and relax about it.