If you wish to pursue information on your Irish ancestors, here are some suggestions:

Catholic death records can be found in the Notre Dame parish burial registers. Protestant records are scattered in the various denominations. Note that some of the records have been lost.

Shipping registers: very few lists exist before 1865.
Much of this information can also be found at; Les Archives Nationales, 1945 Mullin St., Montreal.
The QFHS Library also has several books.

For general sources on the Irish in Quebec, including genealogical, see; The Irish in Quebec: An Introduction to the Historiography , by: Robert Grace