543
“Normal” vi’s(not Chapman’s)Done up nicely, they’re pretty good on a 440-470 combo.
The upper rpm starts to suffer from the small csa when the cubes start getting bigger than that.
Even the MW version is pretty small under the intake valve spring.
On a low deck build where you can use an RB manifold...... they can make decent power.
I feel like they were okay up to about 650hp.
If you wanted to make more...... there are just way better options.
Actually, if you take all the typical VI qc issues into account....... there’s almost always another head that can get the job done, with less headches...... especially nowadays.
Ootb flow for the original std raised port VI’s is pretty weak....... like 240.
The VI is the BB W5.