The holding tanks in my 1999 Concourse are as follows:
Grey tank: 36 gallons, Inca Plastics tank model number H362
Black tank: 15 gallons, Inca Plastics tank model number H229
www.incaplastics.com
Grey/Black tank data for '99 Concourse (may apply to others)
Grey/Black tank data for '99 Concourse (may apply to others)
1999 Concourse