I can't figure this out. Flex plate tightened, all mounts tight, u joints feel good and are pretty new, pig is tight. Vibration is rpm dependent it seems, not speed. I've got 2 videos I'll link here. You can see the speedo and the tach. Around 55-60mph it's a very cyclical vibration comes and goes every 1-2 seconds. When I accel it'll jump to every 1/2 sec then smooths out when I'm going 65mph or so and 3300rpm. Then repeats the cadence on decel. On the video it sounds a bit like an exhaust leak, but that's actually the vibration noise. I feel it in the front, don't feel it in my butt or from the rear at all, which makes sense since its rpm related. I get a bit of the vibes as it gets to the top of the rev band before shifting as well.
Anytime it's doing it if I flip OD on it instantly goes away on the shift.
This engine had been together for decades hooked to a 727 in this car and hooked to the a500 for 10yrs. The First engine with the a500 did not do this that I remember. It developed blow by and I stuck this engine back in. This setup has done it for years, but I'm just getting the car back out from a slumber of 2yrs
Any thoughts?
https://www.youtube.com/watch?v=EXHfeZko0nAhttps://www.youtube.com/watch?v=elas8Yz5hgk
