When accelerating in 2nd gear, or decelerating in any gear, I get a heavy vibration from somewhere in the drive train in my Model A. The engine is a 350 from an '80's Chevy pickup, and the trans is supposed to be a 350 out of the same truck. It's all stock - far as I know. Rear end is Camaro of the same general vintage, coil springs and all. The rear of the trans is in line with the rear end laterally, and almost in line vertically. Looks to me like the differential yoke points slightly under the trans. Haven't measured it, but looks like the driveshaft is about 2½ ft long. I've had the driveshaft out, the u-joints seem tight, and I lubed them. What do y'all think ??

Lar.