[JLMounce]

Does anyone have any information on suggested pinion angles for the first gen's? I know that with leaf springs, some accounting for pinion rise can be taken into account.

I'm trying to diagnose a low speed shutter on acceleration only that my 69 bird exhibits after swapping in a 4l80e.

Using Tremec's toolbox app, I measured the engine down at just past 3*, the driveshaft up at 2.5* and the pinion up at .2*. The app calculates a working angle of .1*

Just trying to cross this one off the list that could be causing the shudder. It occurs at moderate acceleration between 15-30 mph then tends to go away. It doesn't shutter during cruise up to 65 mph. I haven't had the car any faster than that yet, since the trans install.

What are your thoughts? Anywhere else to look? The driveshaft is a new aluminum unit from a trusted shop in town. Trans was rebuilt from a core over the winter, standard fare. TSP lockup converter. Attached to a Summit SFI flywheel that is a year old and has about 2000 miles on it.