system.web.httpexception maximum request length exceeded sharepoint 2010

While attaching a large document ( 65MB) to SharePoint 2010 List gives an error message  correlation ID

ULS Log :  system.web.httpexception maximum request length exceeded sharepoint 2010

06/28/2013 14:28:32.86            w3wp.exe (0x36E4)                                     0x3480                SharePoint Foundation                         Runtime                              tkau       Unexpected      System.Web.HttpException: Maximum request length exceeded.    at System.Web.HttpRequest.GetEntireRawContent()     at System.Web.HttpRequest.GetMultipartContent()     at System.Web.HttpRequest.FillInFormCollection() ………..

Web.Config settings

<system.web>

<httpRuntime maxRequestLength="51200" executionTimeout="300" />

</system.web>

I’ve found that if you only modify web.config files as specified

<httpRuntime maxRequestLength=”102400″  executionTimeout="300" />

Please let me know any impact if I change the above settings and  real resolution for this issue

alancejacob