wheni look at flywheel specs it usually says something like this

engine balance: internal
balance style: neutral

if the flywheel is for an internally balanced engine, wouldn't that mean that the flywheel has no counterweights to it? making it able to be used on my 406 since it does say neutral???then i would just go and get me a balance plate to MAKE it an external balanced flywheel.
also what is a good diameter to look into getting when buying a flywheel? would an 11in fly clear most bellhousings? or is that even the concern when they tellyou that?
i also dont know which tooth pattern to get,(153,168) which matches up to most starters?? like the minis?))

See the answer to the last time you asked this, on the Tech/General board.

An 11" flywheel WILL NOT clear a T-5 bell housing for one of these cars. No way, no how.

Yes you are correct, "neutral" balance means no counterweights.

Incidentally, most 400 blocks are not drilled for the starter bolt pattern for the 153-tooth flywheel. You MUST have one hole added to the block, if it's not already there. Have this done BEFORE you put the motor in the car; so we don't have to see yet another "I just tried to start up my new 70s block motor that I just put in my car and my starter won't work" post, and somebody smarter than me try to explain why there's no possible way for ANY starter to EVER work with that combination of parts. Not a "mini", not some magical one that "ought to" work (usually that comes from people who have never done a swap).