Increasing the number of displayed lines on a single document web item

The standard single document web item has a default maximum number of displayed as 25. We have been trying to increase this without changing the SAP standard objects.

In the class CL_RSR_WWW_ITEM_DOC there is a parameter used called MAX_TEXT_LINES for this purpose but I am having trouble getting a value in there. I have tried adding the parameter in the HTML of the web template but no success.

We are running BW 3.5 stack 11 with BI Content 3.5.2 stack 4

Any ideas on how to pass through a value for this parameter?