Yes if i know what i need.How does the coupler work?Normally the rear mount height is fixed because it sits on the transom.I understand the engine mounting bit.Just unsure how to couple it.Motors aren't in yet.

If the rear mount sits between the block and the flywheel does that mean i don't use the flywheel/mount cover with the factory rear mounts?

Get on one of the parts sites and look up the parts for a bravo motor staggered setup. Once you see the parts, you'll figure it out.
You'll need front and rear full motor mounts.
The bell housing holds a carrier bearing that connects the driveshaft to the flywheel.
There's another carrier bearing on the transom plate.
I've also seen custom setups where a U joint is bolted directly to the flywheel. These flywheel flange/U joints are found in the jet boat section of marine parts catalog. The bell housing is then used to just hold the driveline cover. You dont use a rubber coupler with this, so I'm not sure how well they work.

Fastlane, Here's a picture of my 34 DCB cat. Hard to see but it may help. Eric