Hey Jack, thanks for the input. I have built a front u-joint / front shaft section, round sleeve, 1/4" steel tube, right at the "business" section (under my butt) that is pretty darn safe feeling / looking. it is 2 1/2 times wider than the SCTA requirement. with a solid 1/4" plate beneath my seat.
Then I shrowded the balance (rear section) in a rectangle tube.
I am not as worried about this application, as I would a high revin, real horse power situation.
I am hoping to get all I need done at 5500 rpm, with a couple 6000 shift spikes along the way.
Buick straight 8 -- later model 5 speed -- 25.5" drive shaft.
Thanks again, I think we're on the same basic page.