The Ford crate engines are built with fairly tight bearing clearances, specifically for street use. So you don't need a thick/heavy
oil to maintain pressure. Use a 5W-30 or a 10W-30 and you'll be fine.
If you plan on racing - like road racing - then consider one of the
synthetic oils for better heat resistance. In this country, there are only 4 true synthetics on the market, and Mobile 1 isn't one of them.
If it's going to be your fun toy and week end cruiser, use any good dino
oil and change it every 5,000 miles or so.