Is this "stumble" in a certain rpm range, lets say around 1500~1800 rpms-most noteable in a manual, "kind of" hard to notice in an auto? If you still have the factory vac hose numbers, find where #7 vac hose connects to the base of the carb ("behind" the carb- fire wall side), use a good flashlight and inspect the hose - or use a screw diver or something and move that vac line, is it broke?

 

Im pretty sure it's happening when the car is not warmed up 100% yet.
around 1100 rpm.

if i slam the gas to the floor it wont be much noticeable to the passenger, it just kinda starts going but hesitates.

Think a $10 can of Seafoam would be a good idea?

PS. the vacuum line #7 is in tact and not broken or anything.

 

The seafoam can't hurt anything.

 

ok partner check to see if ur timming is correct?if its ok check distributor cap for cracks,check spark plug wires for breaks,the best way i check for cracks is run engine an with 2 fingers rub up an down the entire spark plug wire do this to each one if there is a crack u will feel it!!! sometimes cracks are so small u cant see them so the best way to find the spark is with ur fingers good luck

 

If I am corect 89 has vac. and mech. advance and thay both need to work So take the cap off and see if you can rotate the roter it should move 1 way and snap back very common for them to stick also check the vac, advance it should hold vac. and move the breaker plate a little repair then set timeing WITH VAC. ADVANCE HOOKED UP If timeing is not set rite all bets are off