forgive me if this has been posted about before, I couldn't find anything answering my question with what I could think to search. I have a 90 740 NA with an AW70L and I'm going to be +T-ing it soon. I'd also like to manual swap the thing, as apparently the AW70 transes don't like boost. as far as I can tell, they never made Regina cars with a manual transmission, so there aren't any direct fit flywheels. I have read that you can, however, use a flywheel that doesn't have any notches on it and have a machine shop machine some into it. I've found a AQ145B Penta flywheel without notches. it looks like what I need but I don't know jack about Penta motors. would this fit on my car and would I need to get some specific clutch if not just for a carbeurated b230? thanks!

 

Your e bay flywheel looks like an automotive flywheel but since boats don't have clutches - there is no way to tell if it is the correct thickness, if the alignment pin holes are correct, if the 6 holes the pressure plate bolts to are correct -

How did you place to replicate the "tone ring" so the engine speed sensor will work?

Why not just do your turbo thing first and see if you can actually make it run - then seek the goal of a manual transmission swap? I'm curious what you plans for a turbo oil return line are.

 

I don't know jack about boats so I wasn't sure if it had a clutch. I do know Volvo Penta motors are just beefier b230s (usually). for the tone ring, I'd take my Regina flexplate and the flywheel to a machine shop and have the holes machined into it.
with regards to the turbo, a +t Regina is not any harder than an lh +t as far as I can tell. the ECU can handle 7 psi of boost before it starts to experience issues. for the return line, there is a blank on an NA b230f where the b230ft has it's return line. I've done tons of research on the +t part.