First of all thanks everyone for their input, it really seemed like a prop shaft problem...sure felt like one, and I have had support bearings seize, destroy the bushing and shake the car like crazy, this felt like the beginning of that.
When the oscillation first turned up I said it felt like a flat tire, so I pulled into a gas station checked my pressures and they were fine...so i posted the symptoms, intermittent vibration that felt like it was in the drive shaft...could feel it in the stick....hmmmm
Checked U joints support bearings etc...all seemed fine, maybe a little sloppy but fine.
General consensus was the U joints might be failing, so today i jacked it up, had another look at the UJ they really seemed fine, and they can't be lubed so nothing else to do. I thought before I pulled the prop shaft I would put the rear wheels on the front and the fronts on the rears because I had a broken belt in a radial front once and it was a weird thing being much worse at low speed than at high.
While flipping the wheels I discovered a blister/separation in the tread of my left front tire.
Why a left front tire problem was causing a prop shaft vib is weird....I didn't feel it in the steering, well I felt it but it was more noticeable in the stick than in the steering wheel, so it felt like transfer to the steering wheel...but really the transfer was from the left wheel to the engine and the prop was magnifying it. Cool huh?
Anyhow popped my spare on and all is well.
For the record I had a low rear once that felt like alignment problem in the front...til it blew up!
Both times I called it wrong I was heavily laden and I think this ads to the misjudgment. When the back is heavy the front is light and things transfer a little oddly.
Also I smacked the hell out of a pot hole last week I think that is what messed up the tire...the roads are horrendous in MTL right now and I'm sporting 165s and driving in a "spirited" manner, I hit a few nasty edges every so often on my commute, and those skinny tires really don't soak it up as much as I would like.
Well a little story on keeping it simple I guess....sure did seem like the prop-shaft though.
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Patrick, '68 220 (used to drive 240s)