Valako built my SBF with These. He said they flowed pretty good. He did minor port work to them.
https://promaxxperformance.com/product/maxx-180-sbf/

Tks Jason - I was gonna reach out to him today and see about options. The stock runner size on the j302 heads is like 170 and probably close to 200 currently. I wanted to talk to jim about larger runners possibly to help slug it down a bit down low under 3,500 or so.

It’s got gobs of torque that’s just wasted almost with current drivetrain etc.