There's a hollow bolt at the end of the boost sense line. When it
clogs up the engine can't sense more boost and doesn't know to
add extra fuel and the car is slow.

Remove, clean, replace and it should be better.

I have a 1982 300 TDT.  I have had situations over the years where the
boost sensor was not working right for various reasons, including
having the connector disconnected.

I would say that tthe power difference is subtle.  I notice that the
engine runs better and accelerates more smoothly and sounds better when
I get it working right again, but I would not say that I notice a big
fall off of power when it is not working.

You didn't say anything about your fuel or air filters.  When either of
those becomes clogged I notice a big drop off in power, much more
noticeable, for example, when pulling a mountain grade, than issues
that arise when the turbo boost is out of whack.

Paul Fretheim