Posting json data of size more than 5MB to WEB API

Am trying to post json to my web api through chrome browser. If the sixe of json is more than 5MB only null is getting passed to the api controller. If its equal to or less than 5mb everything works fine. I changed the IIS->Request Filtering->Edit Features->Maximum allowed content length also to the maximum of 4294967295 bytes. But its not helping.

Could you please help on this?