I guess I will revisit for an oil recommendation for my truck now, after getting the 427w oil squared away. I have a 1983 Ford F-100 with a 300 Inline 6. The engine was rebuilt last year, just a mostly standard rebuild, .030" overbore, .010/.010" on the crank, mild Comp 268 hydraulic flat tappet cam kit, new valves, freshened heads, stainless LT header, Offenhauser 4bbl, Edelbrock 500cfm carb. Since I got it back and broken in properly with Lucas 30w oil, I have barely driven the truck. I need to change the Lucas oil out for some everyday stuff because it looks like the old gal will be towing my car trailer and Mustang to the local AutoCross about an hour away next week and then to Tulsa, OK (about a 6-hour trip) the following week for the track event there.
Since it is a 3-speed C6 automatic (also rebuilt last year along with the engine) with no overdrive and a 3.55 rear gear, the RPMs stay a little higher than I would like while cruising down the interstate. Usually sits right at about 3000 RPM at 65ish.
I do not know the bearing clearances on this one, but they should be close to factory. The factory recommendation was, I think, 5W-30. For these longer trips, do you folks think I will be ok with the 5W-30 or should I go with a good 5W-40 for a little more temperature resistance? Are the rumors about flat tappet cams with synthetic oils ("synthetic oils are too slick for flat tappet cams, they don't allow the lifter to rotate properly") true? Is there a need for extra ZDDP in quality synthetic oil? Should I just switch back to the Rotella 15W-40 I was using before?
Already have the Motorcraft FL-1A filter for this one.
Thanks in advance!
Since it is a 3-speed C6 automatic (also rebuilt last year along with the engine) with no overdrive and a 3.55 rear gear, the RPMs stay a little higher than I would like while cruising down the interstate. Usually sits right at about 3000 RPM at 65ish.
I do not know the bearing clearances on this one, but they should be close to factory. The factory recommendation was, I think, 5W-30. For these longer trips, do you folks think I will be ok with the 5W-30 or should I go with a good 5W-40 for a little more temperature resistance? Are the rumors about flat tappet cams with synthetic oils ("synthetic oils are too slick for flat tappet cams, they don't allow the lifter to rotate properly") true? Is there a need for extra ZDDP in quality synthetic oil? Should I just switch back to the Rotella 15W-40 I was using before?
Already have the Motorcraft FL-1A filter for this one.
Thanks in advance!