Hi everyone,it has been a while since I posted anything but I'm hoping someone can solve my problem. I have a 250 motor, all stock with a 1bbl carburetor and a TH350 transmission. I have a horrible vibration as soon as the car goes on any gear. The moment I put it on neutral or in park, the vibration goes away. It seems to only do this when the car is warmed up. Now while I'm driving, the vibration doesn't seem to be there, but when I come to a stop sign or a light the thing just goes crazy vibrating. Please guide me with some answers.

I will add that I replaced my tranny mount, and double checked my motor mounts. All good.

Is the transmission equipped with a "lockup" Torque converter, torque converter clutch?? If so, you may have a bad TCC switch on the brake pedal or a bad converter, (clutch worn or damaged).

I'll be honest with you, I don't know what kind of torque converter it is. I simply asked my local parts store for one to work with a th350, nothing more. But if it was a bad converter, wouldn't it be vibrating at cold start as well? Because it only starts doing it after the engine has warmed up.

What kind of vehicle is it? Does it have an electronic control module?

The motor is in a 50 chevy car. Single bbl carburetor with electronic choke, and petronix ignition system. No electronic control module.

Do you have a dedicated frame to engine ground cable? Body to ground cable?

Yes I do have both grounds.

Do you have a tuning tach? What is your RPM in park? In gear?

I don't have a tuning tach. And my car does not have an rpm gauge. It's a stock 1950 chevy car.

I did put new spark plugs in this evening and at first it seemed like the problem went away, but after I turned the car off and on a couple of times, the vibration came back. My old plugs were very very dark. I wish I knew how to post a picture of them.

Someone recommended I put in a Langdon Stovebolt HEI mini. Is there another brand as good? Any recommendations?

Have you check the dampener to make sure it is not loose on the crank?? If you think it is a miss fire issue with the dist. you have right now swap it out for a stock HEI Or remove what you have in it now and go back to stock just to test things.

I am getting the new HEI distributor on Friday. Over the weekend I'll swap it out and see how things are. As far as plug wires, I was recommended 1980 chevy truck wires, I'm not sure why. Any suggestions for wires? 8mm, 8.5? Brand?