In web.config file in HTTPUpload site do the following settings.
<?xml version="1.0"?>
<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
<system.web>
<!-- This value is in **kilobytes** -->
<!-- 512000 kilobytes = 500MB -->
<httpRuntime executionTimeout="1200" maxRequestLength="512000" useFullyQualifiedRedirectUrl="false" minFreeThreads="8" minLocalRequestFreeThreads="4" appRequestQueueLimit="100"/>
</system.web>
<system.webServer>
<security>
<requestFiltering>
<!-- This is the value in **bytes** -->
<!-- 524288000 bytes = 500MB -->
<!-- The maximum for this is 4,294,967,295 (3.99GB) - http://stackoverflow.com/questions/4022434/-->
<requestLimits maxAllowedContentLength="524288000" />
</requestFiltering>
</security>
</system.webServer>
</configuration>
Hope this will help.