stumble off the line

[hemihead]

69 charger 383
Car ran great on the bottom end crappy on the top end.

now it stumbles and takes off and rums well to the top end.
Changes i made : new tank 3/8 pickup tube holley red electic pump mounted by tank.
all new fuel line 3/8 dumping into demon 650
Had to adjust idle mixture.
noticed plugs were worn and number was RJ12c
replaced pluges with RJ12YC
Not sure what change is killing the tire burnning.
Thanks Shawn .

[Chryco Psycho]

did you adjust the timing
more advance at idle will make it pull better off idle & but can over advance at high rpm causing missing , if you retarded the timing this would affect both.
If it stubles off the line you may need more pupm squirt to overcome the vacuum drop