crazy vibration @ 70+!!!!...y?!?!

[Muzzy]

ok...after i broke my shaft at the track(as some of u know) i replaced it with an OE shaft. i thought the vibratoin was because the bearing retainer in the center was bent and not quite centered...ok...so i guee i needa 1-piece shaft. i get it..... YEAH!!!!....short lived...as i drove and planned to rip the streets up try it out... i hit 40..a bit of vibration....no prob...kept goin faster...not bad...got to 65... i had flashbacks of the night i broke my shaft and let off REAL fast. shit...i guess its not the shaft...hope it not the tranny!!

anyway...the question is...how can i figure out where it comming from?? it only occurs at 65+. i need someone to ride inteh car with me to figure out if it coming from the front or back.

...soo....anyone got anyideas of how to test it or...possible areas to check??
diff, wheel hubs, lug nuts...idk how i would check the tranny....anything else???

oh...and i can smell hot...or burning oil....i think...or it was someone elses car i hope..ive only done it like twice.