84 Poor Performance at High Speeds

Hey there all,
 
I've had my 84 for just over 2 weeks now and notice that it has very poor performance at anything around 45-50 mph and up. With my foot on the floor it doesn't even really rev it just slowly picks up it's speed. Anything from 65 mph and up is insanely sluggish, to the point of not worth even trying to get up to these speeds.
 
Any Guidance would be apreciated.

fuel filter, restricted exhaust, plugged cat, would be my firsr guesses

why did you buy it?I am assuming everything was ok. when you test drove it before the purchase and now all these problems are starting to show up.Perhaps you need words with the seller.

Sounds like either the converter or the fuel filter is plugged. Checking engine vacuum at a manifold source would reveal converter contamination. Check vacuum at idle, then up to 2000 rpm, should come back up to original reading @ idle and should be around 17 to 20" of vacuum.