Nostalgia Build

I bought a new 350 back early 90’s. It was a beast in it’s day, making the common Honda 300 look bad. I soon rebuilt it due to a rubbing of the radiator hose causing a leak of the coolant. I sold it to a friend who hardly ever rode it and kept it under a shed. Well, after 20 years, I bought it back today. It is in great shape. LOL, the last time it was ran, we pulled it in because it ran out of gas. The carb should be clean. I have been looking for a basic machine to build for a mudder. I have other fourwheelers but wanted a good foundation for a mudder. I think this one is the one. Several reasons, Good solid frame, big open wheel wells, simple basic easy to work on with hardly any electronics, many zerks to keep things from wearing. High ground clearance because of no differiential, large radiator, and chain drive. Chain drive being the main thing that caused me to buy this machine back. Reason being that I can change the gearing for larger tires by changing sprocket size. So, I will have questions that I hope to ask here. I will keep everything in this thread along with pictures. Any help will be much appreciated. To start with, I don’t trust the oil injection. I will bypass and remove it.
What mixture should I run?
Any good sources of info I should know about?
Are parts hard to find?
Anybody built one before? lifted, large tires
Open up of restricted exhaust and rejet?