[dpoltzer]

1974 T/A 455 and a TH400 with professional rebuilt Qjet. Problem is a slight off idle stumble but otherwise motor runs well. I believe the issue is with the distributor which is a Pontiac unit of unknown original application. It is a points type distributor. Carb has no stumble in park but in gear is when the stumble occurs. Rebuilt engine makes 18 steady inches of vacuum and initial timing is set to 12 degrees BTDC. The dist. weights move freely but the springs seem to have very little tension. I don't know if I should start with stiffer springs or perhaps a different/correct advance unit. Best place to start?? Thx.