1.) How many miles are on it? No more than 12,000 miles, maybe even less.
2.) What did you have in front of it for motor? An oval port 3L, don't know why this matters?
3.) How much does it weigh? Not too sure, it is a Spec aluminum flywheel, I can weight it sometime this weekend for you if that matters that much, I run it on my track car as well, it is considerably lighter than stock.