Round Hood hood rattle / vibration

[squonk 43,800]

My 704's hood rattles /vibrates something awful. Mainly at the higher throttle settings. It's quite annoying. I have the hood off of it now trying to diagnose a fuel issue but that's another story. I may have solved that but I'm not going to jinx myself yet. The bottom mount is solid no broken welds. The 2 holes by the steering wheel has some small cracks and i welded washers behind them before it was painted. I'm using the std issue thumbscrews. I have though about using some rubber washers and some spring washers to try to soak up some of the vibes. I was wondering if any one else has tackled this problem and how they resolved it?

[Kelly 1,033]

I have used cone washers with a rubber back on them, I get them at Fastenal, I tried O rings that works as long as you don't take it off often. 

[squonk 43,800]

Do you use them under the hood or under the bolts?