Dell Venue 7 ROM

Well, I have been looking for the full firmware pack of Venue 7 3730 on dell.com and google.com for a very long time. Anyone please tell me how to find them?

This is the first time I can't find any firmware pack from official or custom. Why hide them so deep? Never allow anyone to mannually change the system version for their own tablets?

Venue 7 3730 is a good machine, but with some little bugs and bad support. So, please release the system pack and let people customize it for better use.

Thanks.