I looked for 73 and 74 Cudas this weekend but didn't see many that I would consider using as a referance. There were a good number of 72's though.

One I looked at had the back of the bumper flush with the front of the filler strip. The second one had about a 3/4" gap just like yours. So, I think the way you have it now would be OK. It's probably at the high end of what's acceptable though.