Ted Hamilton
Helmet Painter / Racer
Bob Berlin can hook you up....or any local machine shop. For the big boys I'd get a 3/4" billet plate, map out the bolt holes, drill and tap, and then CNC mill (or manual) some out from the underside, leaving plenty of thick webbing to keep it rigid. Or try this:
https://www.bmikarts.com/Motor-Mount-Plate-INTEK-305-GX390-13HP-Predator_p_1126.html
..and another option:
https://www.ombwarehouse.com/billet-engine-adapter-plate-for-db30-to-big-block-8-13hp-engines.html
https://www.bmikarts.com/Motor-Mount-Plate-INTEK-305-GX390-13HP-Predator_p_1126.html
..and another option:
https://www.ombwarehouse.com/billet-engine-adapter-plate-for-db30-to-big-block-8-13hp-engines.html