[QUOTE]Originally posted by NTFDAY
[B]The extra weight is on the flexplate not on the dampener. The dampener has a machined groove/channel approx half of the circumference of the dampener. One other note, to my knowledge no 400sbc came with a standard transmission. To run a standard tranny behind a 400 sbc you will need a flywheel from a 454 bbc as they are also externally balanced. [/B If you look at the back of the balancer there is a section like you said a half moon but it sticks out maybe 3/8 of an inch.Yes there is the extra weight also weldedto the flex plate.A manual transmission was available with some of the trucks.