Tank - Briggs 4930 or 4920 Color:Harvest Gold They both fit the same

They both fit the same

Tank Size: 20" x 8"

Note: Gerber had an older version of the Viper toilet which looks nearly the same but the new lid and tank are slightly smaller and not interchangable

Tank Size: 18

Tank - Briggs 4930 or 4920 Color:Harvest Gold They both fit the sameManufacturer: Briggs Tank P N: 4930 or 4920 Rough In: 12" Bolt Width: 5. 5" Flush Valve Diameter: 2. 5" Gallons per Flush: 1. 6 or 3. 5 Internal parts and Briggs 7421 tank lid available separately. Why 1. 6 or 3. 5 GPF? Briggs made this originally as a 3. 5 gallon per flush toilet, and then during the changeover to 1. 6, they kept the porcelain the same and just changed out the internal parts to restrict the amount of water that would fill up in the