think baby needs a bottle
You can run 100 shot easy on a stock 340. The more you go the more the risk.
10.5 is pushing it on pump gas. A little detonation goes a long way when running NOS, and a little lean is just as bad.
If you go lean or detonate plan on rebuilding.
On the rev-limiter thing..... The big deal is when you have a limiter that cuts fuel. This changes the NOS/fuel ratio and can blow your intake through your hood.
With that said.... Cutting the spark isn't a great idea.....
Like i said and others.... You need things right because when they go wrong, they go VERY wrong.