I’ve written about how to cite block quotes in MLA format before and noted how the Purdue OWL gets this wrong. As demonstrated in the NFGW (our comp 1 text) and in the MLA Handbook: 7th ed 
(the newest edition in the writing center), block quotes get indented 1 inch on the right (See image in right, taken from page 94 of the MLA Handbook.
APA format varies on how far we indent the block quote, but MLA’s 1 inch serves at least one purpose. If a paragraph began or ended with a block quote, the reader would not know paragraph boundaries based on indentation unless we indent 1 inch. Furthermore, it is an objective measure according to an agreed on format. We get so few objective measures in writing that we shouldn’t take them for granted.
The Writing Center does follow MLA format regarding block quotations in their pink handouts. Big ups for the JCCC Writing Center! If anyone tells you differently, have them show you documentation why.
Go to the source. Ultimately the writer is responsible for their grade, and additionally, the instructor sets parameters for grades.
I choose to follow the MLA handbook as closely as possible.
