on my 79 coupe deville, which i have just completely tuned up, (80k miles) there is a slight hesitation when i accelerate. When the car is around 50mph it runs perfect and responds perfect. any ideas?

First thing I'd do is check the accelerator pump. With the engine off, take the aircleaner lid off, look down the primaries (2 smaller holes towards the front of the carb) and open and close the throttle a couple times as if you were hitting the gas pedal. You should see gas squirting out from the front of the primary barrels.

alright sir, thanks for the advice. if gas does squirt out, what would I look to next?

secondaries. Check out the secondary air valve "damper." Its the little vacuum can on the side at the front of the carb that also serves to slightly open the choke when the engine first starts. Also limits how fast the secondaries can open to prevent bogging. With the engine running, try poking the secondary air door at the back of the carb. It should feel solid and not want to move. If it opens, replace the little vacuum diaphragm that controlls it. Usually this is sold as the choke pull-off cannister.

Also, check the air door tension. See this link, bottom of the page: http://www.73-87.com/7387garage/drivetrain/myqjet.htm

BTW: if your Caddy is running a stock engine, I wouldn't go changing the metering rods, because GM generally did a good job of tuning the stock carb.