New heads?

I would consider a 385hp 360 a pretty mild build(btw...... how are you determining you currently have 385hp? Dyno? Track results? Rough guess?)
Assuming the combo is some variation of the typical components that would be used to get you to that point, I wouldn’t expect a set of different heads...... and NO OTHER CHANGES......to make enough of a difference in power to justify the expense.

Imo, a better approach would be to figure out where you want to end up, power wise, and then make up a list of the changes you think would be required to get you to that point.
Then..... start buying some parts.