extended fuel tank for C class

MDEECUSA wrote:
I have a 2021 jayco gray hawk Ford E450 chases can I install a larger or additional fuel tank?thanks for any help

The short answer is no, not easily and I'm not aware of any mfgs like Transfer flow that make larger drop in tanks.
Are you thinking something in particular, or haven't even crawled under it for a peek see?

That is, unless you have the 40gal tank, 55gal is a factory option. But you didn't state which you have.