Help with Rear end gear ratio

I am building a bracket car for my wife. 1974 Dart Swinger. Strip only. I have a set of Good Year 30x10.5x15 that I will be putting on it. It will have an 8-3/4 housing, 727 Trans and a Mild 318 to start to get her some seat time. The goal is to get her seat time this year and then build a 360 for some HP to get her into the low/mid 11's. I am planning on doing a Spool but have no idea what gear ratio to use. I have been told 411's and I have been told 430's anybody have some advice that I can sort this out. If you need more info that I have not provided please just ask.

Thank you