340 Full throttle hesitation

You may want to consider getting one of these. It's a dead stop tool. It's used to find your true TDC. This will take out any variation error in the crank, and the vibration damper. (Sometimes the outer ring on the damper spins from the inner ring and will throw off the marks with it). It's a good idea to get a piston stop to find the true TDC. It's only $8...

http://www.summitracing.com/parts/sum-900189

Beware of the Mopar Performance and Comp Cams TDC tool. There was a batch of bad ones going around a few years ago, and there could still be some out there. The spark plug threads on the tool are off and they will not thread in. You can't correct them with a die because they are hardened.

The top dead center piston stop tool just threads in the #1 spark plug hole, then you screw the inner screw down and then turn the engine over BY HAND until it stops (removing all the spark plugs makes it easier to turn over with a wrench). Mark the vibration damper for where it is or take the reading. Then reverse the direction and spin the crank until it stops. then take that reading. Then take the difference between the two (find the middle) and then that will be your true TDC.

Finding true TDC is important to getting your timing set properly.