this might belong in advanced tech....
my understanding lt1 is balanced by flywheel and crank pulley/dampener whatever its called
so i have a stock motor with a zero balanced flywheel and a vibration....what my fix????????
stock flywheel from junkyard or oreilley? or tear the motor down and redo this...?

 

The damper has nothing to do with the balance on a stock LT1. They are balanced by thr flexplate/flywheel on the rear. If you have a nuetral flywheel/flexplate on a stock rotating assembly that will cause your vibration. Any stock one will fix it for you, they're all the same as long as it's from an LT1.

 

is there a way to have mine modified since i just had it surfaced ect and i dont wanna pay 130 for a new one...

 

I've yet to hear of someone adding wieght to one of the nuetrally balanced flywheels, but I'm sure it can be done. Just take it to a machine shop and ask them. It doesn't have to be balanced with the rotating assembly since they are all the same.

 

stuff stinks...it was the flywheel...but i got a new gm piece for 145...so its ok...put it on and its smoothe as glass..then trannys on its way in now...
heres a pic of the 2
new piece on the left

 

Sorry ya had to spend another 145 bucks, but at least your car is fixed now