Fuel pump or timing...???

[chukis85c10]

Not sure what is causing the jerk when truck warms up. Truck starts up fine and runs fine. As soon as it warms up, it jerks while sitting at a light or in park. The temp doesn't go over 170/180. It did not want to start yesterday after getting from work. I put more gas in it and it started up fine. As I mentioned, idles and runs smooth before it hits 180. Truck does not stall on highway or when driving. Oh, I also here a dripping noise from inside the tank when I turn off truck. Almost like drops falling into bucket after it rains. Jerking gets worse the longer I drive the truck. Excuse my rambling, just thought I would mention everything.

This is the setup I have.

1985 Chevy
5.7 350 - (86-95 block)
iron non-vortec heads
Edlebrock Performer intake
Edlebrock Carb
Mr. Gasket electric fuel pump (sits outside, just below tank)
HEI distributor

It's the first time I run a setup using an electric fuel pump since the block did not have the setup for manual pump. Not sure if the fuel pump could be affecting it. Any ideas?