Boat motor?
I'm afraid a leveling carb spacer for the marine intake would need to be custom made.
A lotta marine engines use a wedge spacer to achieve that marine angle,, so it may be it can be removed,, or a second one reversed and added to make a hi-rise,, The wedge spacer is readily avail, have used a few..
Is the block any stronger than a regular 340? I wasn't planning on using anything from it except maybe the crank and rods. Its been sitting for couple years and has surface rested now. I only paid $50 for it. And it came with a new engine stand.
I don't believe the block is any different,, but you can use the block, crank (with knurl polished off if nec) rods, etc.. the used pistons would have thrust wear on the opp side of pistons,, but could be serviceable, I believe.. and they'd be low comp..
I'm ignorant on the subject but what exactly makes the motor spin the opposite direction. Is the firing order backwards?
As mentioned,, the cam is diff,, as is the starter and drive,, the alternator fan,, the distributor, because the cam turns opp direction, it tries to push the int. shaft UP,, so dizzys have mods to accept thrust, if the automotive style water pump is used,, it'll have a different ,, or non directional impellor.. firing order backward,, and often a low profile dizzy cap.. I prob forgot something..
hope it helps
