Re: I'll never stop "improving"!
Hi Skinny, welcome to the forum from Dallas.
As usual Tom's advise is golden. I'll just elaborate a little on some of his comments. An important thing to know about oil ratio, is follow the oil manufacturers recommendation. Most dino based oil will be about 32:1. Synthetic is usually 40:1 - 50:1 and up.
The best modification I did to improve bottom end was to add a expansion chamber from SBP. Varying the length of the header changes where the power band is strongest. The longer the header pipe, the lower in the power band were the expansion chamber starts working.
A Speed carb is a good investment for smoother idle, and less 4 stroking. It uses the same throttle cable, and tuning is close to the same.
A good spark plug is a NGK B6HS, and sometimes a NGK BP6HS, which is extended tip. It's a good idea to buy your own spark plug wire, and cap at a auto, or motorcycle supply.
I assume it's about as flat where you live as around here, so I would recommend a 36T rear sprocket. With that gearing on 26" wheels you'll be able to cruise 35 mph for extended periods without over revving you motor.
You're probably going to want to buy a 66, and 68 jet. I run 66. Stock kit jet is about a 70.
Keep a close eye on all your nuts and bolts until you figure out what's most likely to fail or come loose. Especially keep an eye on your head bolt torque. The head bolts need
to be re torque 4 or 5 times in the first 600 miles or so. After that not so often. Be aware the acorn head bolts sometimes bottom out on the cylinder studs. It's a good idea to check them for clearance, and if necessary add washers under the acorns, or change them to open nuts. Most people torque the head bolts to 125-145 inch lbs. I use 125 in lb.
Hope you bike runs well for thousands of miles.