Would this replace the stock pump?
 

As a practical matter, no.

what you mean as a practical matter ?

Don't do it.

ok it just seemed cheaper than a new stock pump

won't work, unless you really feel like tearing and getting luck and not break the plastic pieces holding the pump togather. to fit that in.

The Cavy has a smaller gas tank.

There is a better and cheap replacement out there. Delco pumps suck. Trust the guy that's on his 4th one ;)

Uhhh, No. They're interchangeable even.