I've got a 68 with a 350 Gm crate and a TH350. It has a pulsing vibration at speed. My guess is that it takes about a second to make a cycle and is anoying at highway speeds. I'm trying to figure out a plan to find out what is going on. Where would you start first?

Thanks

Solid motor mounts? Is it only at specific rpm's? Have you checked your drivetrain angles?

Yep, drivetrain angles.

check those u-joints just finished removing my new joints only to find one needle in one cap had fallen over and gave me a gallop type vibration.

A pulsing vibratrion on my dads truck drove him crazy. He went through several mechanics untill it turned out being the transmissons torque converter.

A pulsing vibratrion on my dads truck drove him crazy. He went through several mechanics untill it turned out being the transmissons torque converter.
+1. Torque converters arent the first thought! If it is so a nice hole shot converter should make you very happy.

Motor mounts are not solid and ok--driver's side recently changed.

I think the drivetrain angles might be a place to start as the rear is new (a Nova 10-bolt) along with replaced springs, bushings, etc. I did have the driveshaft balanced when it was shortened but I never checked the angle. I'll check the U-joints as well but they are new.

Thanks for your comments.

Steve

i have had the torque converter do the same thing!! Changed the brand new converter out after checking everything under the sun and surprize!! no vibration. Im not saying this is your problem but after checking everything else out check that