Alright guys im just tryin to plot my next move.. or.. my course of action.

im going to attempt to keep this short n simple

alright so right now im having some pretty nasty vibration when accelerating, seems the harshest in 3rd and 4th, when i hit 5th even in the pedal the vibrations cease..

1st from standstill with low rpm is giving me a semi bad, id say a 3 outa 10 chatter, but im assuming thats normal with a stage 3 clutch, BUT i got under the car and with the ebrake locked and wheels chocked had someone ease out the clutch to recreate it and what i saw to my surprise was, it was the driveshaft causing it,, not the engine kicking in its mounts like i was sure it was, no the drive shaft is... hmm how can i explain this .. lol, it was turning perfectly cylindrically but it was like it kept hitting something made of rubber when it got like halfway through its rotation, it was bouncing back like a quarter of the 3/4 it just tried to spin and doing it over n over,, im not sure if it was actually making a rotation or not but.......... thats not the normal source of chatter right, couldnt be... its from the disc to flywheel which cause the motor to jump, right??? (my mounts are modified and dont give the engine much "wiggle room" which is prolly whats caused the rearend to take a ****, if that is indeed the case)

its gotta be my rearend huh? low fluid in the trans wouldnt cause it right? what about bad cv axles? its got the IRS... which is why im trying to make sure ive got the right idea before popping the lid off that pumpkin.. cause im not looking forward to dropping the whole damned IRS assembly

now... if it is the rear diff what will i be looking at replacing? id like to go ahead and get an idea price wise if someone can within reasonable doubt tell me what they think the issue is,,, also... if its the **** that gives it the electronic positive trac, which i think it must be, can i weld it solid?,, i know id have some issues with it being completely solid but rlly idc

thanks in advance!