In the continuing saga I have removed all the smog off of my 73 E-200 and, put a fresh tune-up on it, all fluid levels are fine, and everything is as it should be. My problem is it vibrates quite a lot when taking off from a start. After I reach 40 mph it smooths right out and runs just fine. On the freeway at speed it just purrs along as fast as i need to go. It's a 302 with a fresh transmission and torque converter, and a recently balanced drive shaft. I can't help but think that it's the carburator. Any thoughts, Thanks Everyone----SDRMike

Mike, do you feel the vibration only when the van is moving?.. Or is it also there when revving the engine in neutral?.
Was the flexplate on the crank changed when the trans work was done?.
How does the vibration damper on the crank look?.
Have you checked the torque converter to flexplate bolts?.
Did this vibration start after the trans and driveshaft work was done?.

I've probably mentioned this a thousand times before, but I had a 76 plymouth that I swapped a 360 into (had a 318), and didn't know that the torque converters were different (one had a balancing weight on it, the other didn't) and it did the same thing you're describing.
With Fords (at least on ours) the weight is on the flexplate, and there are (I think) 2 different ones. One has a 28 ounce weight, the other has a 50 ounce weight.

If you think it might have something to do with the flexplate or torque converter, I wouldn't drive it until the problem is fixed. I ignored the problem on my plymouth for too long, and it tore up the front seal in the trans.

The only time it vibrates is when starting off under load. If I baby it real slow under load it is fine, very slow acceleration but no vibration. The vibration has been there since I bought it. I did a 300 mile trip this weekend, all on the freeway, and once going at speed it is smooth as silk. I still think it might be the carb, Thanks----SRDMike

Sounds like one of 2 classic vibration problems... Either your u-joints are going bad or you need your tires balanced. Both of these conditions typically cause vibration that will eventually smooth out once you start cruizing at about50-60 mph.

Randy B