Surging 327 Chevy

My 327 CI (340 HP) 68 Chevy has a Saginaw 4 speed, and an 8 inch Ford rearend out of a 76 Maverick. The car is a steel bodied 23 Model T Ford Roadster that started out as a Roadster Pickup. The box was removed and a rear section from a Touring Sedan was added making it a big two passenger hot rod. I have 202 heads and Sanderson headers along with an Edelbrock 750 CFM carb and a K&N air filter. I just finished doing a tuneup on it and it seemed to run fine but has now started running rough and surging after the motor gets warm (around 180 degrees). What is the probable cause of the surging. I have not opened up the carb yet. Thanks in advance for any and all help.:mad:

"" I just finished doing a tuneup on it and it seemed to run fine but has now started running rough and surging after the motor gets warm ""

If it did not do this before your tune up, double check everything you did, make sure all vac lines are on, and right and such.

Was the tune up just for the maintenance of it, or was there something you were trying to fix?

Surging...at idle, at speed, what speed/revs/gear, etc? under load, cruise, decel?

your problem could be caused by a number of things

1. is it a new carb? if so may need to adjust the floats.

2. fuel pump going out is it electric or mechanical?

3. clogged/restrictive fuel filter

4. trash in carb floating around clogging jets

5. trash in tank causing loss of fuel

6. trash in fuel pump blocking fuel

7. does it have vacum or mechanical advance?

8. could have a old vacum hose or gasket leaking after engine warms up

9. and many other things could make a surge too