Nitrous on a 340 100 shot

Not close to what was written. My comments ONLY have to do with the juice kit. The carb may be just fine at 7 psi.

If you don't have the kit and instructions, you are asking questions that are in those instructions. There will be a tune up. A regulator on the fuel side of your kit will likely be necessary. I bet the instructions are online. Simple enough to see what is suggested.
Thanks for your advice and input I'll download the installation instructions and see what they say.