I believe it's rather impossible if you really like to make it one piece. the engine vibrates whereas the rear end is bolted to chasis so there is a length problem, as well that thing would be REALLY heavy and hard to work with
"Too long, flex?" That was my thought at first too but if you look at a pick up truck they run a lot longer length and they produce just as much torque if not more.
I think a 1 piece shaft would be a lot lighter cause of losing 2 joints and hanger bearings.
its been discussed in detail, tried also...its too long.
a 2 peice is just as affective and eliminates the lobro joint and the rear carrier bearing and 1 u-joint.
Weight is far less without the lobro joint. And it can be made of aluminum also for those of you with deep pockets. Cost for a steel 2 peice is around $350.
Do a search for driveshaft and you'll find the other posts.