What hose sizes and routing tips simplify LS radiator plumbing?

Sizes and sides:

• Upper hose: Speedway: LS upper hose is 1-1/4 in (smaller than SBC/BBC) — ICT Billet says the upper hose connection on all LS pumps is 1-3/8 in; verify.
• Both hoses on the passenger side on most LS engines: Most LS water pumps have both inlet and outlet on the passenger side; LS swap radiators put both ports on the passenger-side tank.
• Thermostat low on the water pump, in the lower hose.

Routing tips:

• An adapter from the LS upper outlet to a 1-1/2 in radiator inlet lets you use common radiators and hoses. Speedway's LS swap radiator hose adapter (listed at $24.99 in its article) fixes both problems at once: a 1/4 in hose barb takes the steam line, and it adapts the LS water pump's 1-1/4 in upper outlet to the 1-1/2 in inlet on a typical radiator.
• A double-pass radiator puts the upper outlet on the correct side for an LS.
• Always plumb the steam line — LS thermostat sits low on the water pump, so a steam line is needed to purge trapped air; most LS swap radiators have a steam port, and adapters let universal radiators work.
• Check the accessory drive and pump you're running: pump outlets differ (see which water pump).