At 130 gallons, the B356 is the flagship fresh water molding of this range - a 60 x 30 x 18 inch block sized for the builds where water is the mission: full-time coaches, expedition trucks, mobile wash rigs, off-grid trailers. The arithmetic is the spec sheet's loudest line: 130 gallons at 8.34 lb per gallon is about 1084 lb of water. That is over half a ton riding in your chassis, and it makes tank placement a suspension and axle-load question before it is ever a plumbing question. Mount it low, center it between the axles, and check your ratings.
The molding itself is FDA-compliant polyethylene for potable service, rotomolded in Tustin, California by a company that has done nothing but this since 1974. It ships as a blank: five feet of tank with no ports until you say where they go. Print the drawing below, plot fill, vent, outlet, and sender with the fitting planner on this page, and Ronco spin-welds or thread-installs each fitting to your marks before it leaves the plant.
Shipping a 133 lb, five-foot tank is genuine freight - run your ZIP through the freight cost estimator before you commit the budget. If 130 gallons overshoots, the step-down sizes are all in RV water tanks, marine installs should start at boat tanks, and the complete line lives on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B356 dimensional drawing - print it to plan your install and mark exactly where you want fittings located; Ronco installs spin-weld or threaded fittings to your marked spec.
