68FordTruck, you already have a 390 in the making... or a 410. A 360 block has a 4.05" bore with a 3.50" stroke. The 390 uses a 4.05" bore and a 3.78" stroke so all you would need to do is swap in a 390 crank, rods, and pistons.

If you want to build a 410 (4.05" bore x 3.98" stroke), it's gonna take another part. The 3.98" stroke crank from the 428 is externally balanced so you will need the flywheel / flexplate with the offset counterweight.