Consider your lives when building/ buying a hotrod
Hollow? Ductile cast iron...they are out there. Forged tube axles are $40 Cheaper?
Zig's Street Rod - Suspension - Front Components
I-Beam Axles from Zig's street rods.
Cast from high strength 65-45-12 ductile iron, Super Bell's I-Beam axles are designed to accept '37-'48 Ford passenger car spindles.Applications include '28-'34 Ford, 1/2 ton Ford trucks up through 1941, and '35-'36 Fords when you split the original bones. Split wishbone kits and instructional sheets are available.
Imagine that on a 1/2 ton truck....~!