Use this application to download into your iPhone contacts from your Google account, without any limitations on the number of contacts to be downloaded. This is NOT a synchronization app, i.e., no information gets deleted in your address book, the application either adds new contacts or modifies existing contacts by adding new phone numbers, emails, and by updating the profile picture. If you want to SYNCHRONIZE your Contacts, you can do that on iTunes.
ADVICE: Create a group on GMail with the contacts you want to download and select that group.