a jasper remanufactored engine is being installed in my 2004 dodge ram pickup truck would it be wise to use synthetic oil after the break in peroid? and how many miles should i change the oil?
I would use what ever oil jasper says to use.
And change the oil at least as often as jasper says to, time or mileage, whichever comes first.
Either regular or synthetic will work fine with 5000 mile changes. You might stretch synthetic to 7500 if you rack up a lot of miles on the highway quickly.
I’d go one full oil change with conventional oil before switching to synthetic.