This might be a stupit question, but what is the best oil for these 5.4 tit. expos?
I run mobil 1 full sec. in my bike, but is it go to run full syc. in these big motors?
any input would be good.

 

If you drive normal.. any oil that exceeds the manufacturer spec "should" be ok.
stick with the major players..if you drive "hard" same as above for the oil..just add a good cooler to the truck..

thats my 2 cents..good luck ..and change oil often..