If you have anything but a Rubicon/Hard Rock/COD/10A (D44 front axle) then you will have a D30 front axle, what should not run 37" tires. If you have a $10,000+ budget you can get a D44 front axle and 37" tires setup correctly. If not get 35" tires and and you can C-Gusset, truss, sleeve and ball joint your D30 to play it safe for the lightweight front axle. Not all that is needed but would add strength to a possible bent axle down the road.
The "D44" in Rubicon Jeep JK's is not a true D44 with all the trimmings. It and the D30 share the same:
Axle tubes
C forgings
Ball Joints
The major downgrade in weakness is the Ring and Pinion size and the axle shaft (spline count).
Doesn't cost anywhere near $10k to do it right, unless you farm everything out to a shop. Maybe close if you're counting the cost of the lift and wheels, tires.
If he's not wheeling it hard the D30 will be okay for a street DD Jeep. Gusseting the C's is advisable, especially given the low cost of doing so. And I'm saying street DD Jeep because of post #1.
And don't confuse all that with saying it's ideal to run 37's on a D30. It's not.
OP...I'd keep a regear down to 4.56 and no lower (numerically higher) if you're gonna wheel it some with 37's on a D30...and cryo them to boot. It's inexpensive to get the cryo treatment and puts SOME strength into the R&P.
Plenty of folks have 37's on D30s and don't grenade anything. A lot of it has to do with careful planning and being conservative in your driving habits.