As I understand, the only differences from v6 to v8 is the size of the uni joint. Theoretically it should fit.
Not sure about tail shaft. Fixing things and upgrading them, gonna put LSD in and figured v8 tailshaft would handle more torque
Personally that's the last thing I'd worry about. Plenty of boosted 6,s about, pushing around 300rwhp that don't blow driveshafts. Given your doing to yours what I've done to mine, I can assure you the driveshaft doesn't bat an eyelid
v6 one would be fine, unless its warped/twisted/etc. because you're not really pushing more torque though to the rear diff. the diff will only be transfering said torque in a different matter. wouldnt be surprised if your tailshaft was originally designed with a LSD in mind with all the other v6 models out there.
you couldnt bend a tail shaft with 6 horses behind it ha. Wouldn't touch it unless your unis are buggered
