I swapped a manual flywheel from one motor to another with no ill effects. Maybe I was just lucky. The flywheel debate has raged on and off for a long time on this board...no? I have a complete 4-speed set up and am looking for a good 300D to stuff it in one of these days. I'll let you know how it works out.

But back to your question. My manuals are at home so I don't know the exact spec., but make them tight...as tight as you can get them with a fair size ratchet. And yes, use locktight. Remember it's a shaky diesel...always use locktight.