Recently I replaced a clutch in my 96 N/A that had been ground to the rivets by the previous owner, and had the flywheel machined. Put everything back together and about two months later a strange vibration would be present from around 1000-1500RPM. The vibration eventually spread out so that it's now there all throughout the RPM range. I pulled the trans back out and am now taking the clutch and flywheel to be balanced (I thought the alignment pegs meant it could only go back together one way, preserving the balance, but I was wrong) and am now wondering- is the flywheel internally or externally balanced? I'm hoping that fixing the flywheel/clutch balance will solve my problem and I won't have to tear the engine down and see if my engine/flywheel balance is the issue. Thanks!

does it hapent going down the road or just sitting