Proposed 400 bb build, cam recommendations

The only stock stroke 600hp BBM 400 combo that comes to mind is one AndyF did for a friend of his several years ago.

RPM heads with some amount of porting(may have been MCH CNC), dome pistons for 12:1-ish CR, .651” lift UD roller, Victor(?) intake manifold.
I recall it making just over 600hp.

For sure, a bread n butter 400hp build with a 200 shot will be cheaper and easier.