finally got some pics that are clear, will give you a few options,
this is a 6 cyl but the idea is the same for a V8
the motor was coupled to a stern drive and used a duplex chain not a bolted flange,
note the plate to secure bearing


if you have side bouancy tanks that form a floor then I use an angle iron frame,
this one is ally, side mounts and soft clutch buy or make,
replace gear on gearbox front shaft with a flange and bolt to jack shaft
need to make a plate to hold bearing and mount to frame

this one is solid mount to the jack shaft so V drive would need dog clutch
front mounts stainless plate
casalle angle V drive, partially dismantled

another way of mounting at the front, bolts on behind the harmonic ballancer,
this one bolts to engine bearers have one for the rear as well but didn't find it