Revisiting an unknown vibration issue

[FTA1995]

Hey guys,
Got one more tricky one to bring up,
Some of you might remember a thread I started a while ago about a suspect driveline vibration,
http://www.f-body.com/forum/showthread.php?t=22972

Since then I have added 6 point sfc's, a built t56, and a chromemoly driveshaft. Keeping this really simple, it sounds like this loading vibration only happens at wot, any rpms now. Is it possible that the vibe could be tracking from the rear end? It almost feels like the case and axel tubes are flexing from the force, and sending the pinion out of alignment. My gear is starting to whine(or whir) at me under load only, deceleration makes no noise at all, since this ten bolt can't handle abuse, I never launch or otherwise do anything stupid with it, if I can help it.

I will check again any other system that could be related again; my driveline is in phase, my mounts are not torn, my balancer is correctly installed(no missing weights from what I can tell, my flywheel has been properly machined, my pressure plate balance checked, I'm unsure of where else to turn. There are NO bad vibrations or sounds if I rev up the moto at a stop, stethoscope did not turn up any positive results either.

any ideas?
Thank you guys

[Joe 1320]

I still recommend checking the pinion angle.

[FTA1995]

Well this is embarrassing :/
I got rid of my Bosch platinum 4+'s today, they were very burned and fouled, replaced them with Ngk tr55's. Those Bosch plugs were causing a very large amount of the vibration disturbance I was feeling through the beginning of the torque curve, and it's helping me isolate the other noises much more precisely, by feel and ear. There is still something to worry about, but it seems much less malicious with that culprit plug set out of the picture. I will get a different angle finder to check the pinion/transmission-crank angles again, if things continue to go the way they are I might have enough spare cash for my s60 rear

Side note; I have never once had a Bosch part that isn't complete crap; I gave the gimmicky 4 anode design a chance, but they lacked in every category you could score them in, I'd much rather run through 2 sets of tr55's than go through that crap again!

[FTA1995]

I still recommend checking the pinion angle.

Is it acceptable to use both the forward and rear u joints to find centerline/pinion angle when the yolk bearings are in a vertical position? I'm going to get a new dial protractor right now.