One more 416 What will it do ?????/
Lunati probably based gear recs on a stock stroke 340-360 engine. 340-360 will generally pull more rpm than a 4" arm stroker with the same cam/parts, thus the higher numeric ratio.
I know guys using 4" strokers running high tens/low 11's with same cam, 275/60, ss springs and 3.91 gears. Mid to high 1.4x 60's.
Go have fun with it and make adjustments as you go.