The A3000 has a 57.17mm compressor, which ATS rounds up to 58. The stock LB7 turbo has a 59.9mm compressor......
We'll be putting an LB7 on the dyno soon with manifolds, up-pipes, downpipe, and 3.5" inlet on a stock turbo. We've done 540+ without any of those airflow upgrades on a stock LB7...