I went with the ford performance short block, beefy block, revised oiling, 4 bolt mains, Cleveland mains, plus steel crank, H beam rods and Mahle forged pistons all balanced and assembled. I assembled the rest of the engine with better AFR heads and special Comp cam and valvetrain. Engine is amazing, I couldn't be happier.
https://performanceparts.ford.com/part/M-6009-427F
One word of advise, the long block comes with a nice 8" deep
oil pan, but you should really go with a 7.5" pan for proper ground clearance. Have fun building your car !