No affiliation - Eaton twin screw and 32v manifold for sale
 

Asking price is $1100.00 Purportedly run for 5 hours of dyno runs for use on a marine 32v engine:

https://www.pca.org/classified-ad/325471

The Porsche 928 Marine Engine was an S4 based engine. As such, the shape of the intake ports would differ between S3 and S4. I have no idea what engine the seller put this intake on, but the manifold is not much more than an aluminum box....