So this might be hard to convey without anyone being able to actually ride my bike and feel what's happening. But I'm concerned. Sammy is my only form of transportation.

You know the feeling of the engine lugging when your RPMs are too low for your current gear and you need to downshift? Starting with 3rd gear around 35mph the bike feels similar to that. It feels like the motor is working harder than it is supposed to be. But everything sounds like normal.

This past weekend I had two rides of 200 miles each, one on Thursday night and one Monday morning.  Almost all of it at 65mph on the highway. I didn't have this issue before the weekend.

Monday afternoon (a couple hours after the 2nd 200 mile ride) I had to ride to work, 20miles each way.

Going into 4th it feels even worse. That lugging feeling continues through about 55mph in 5th. I'm NOT shifting too early, it's not actually lugging. The bike sounds fine and the engine speed is where it should be. But even all the way through those gears I still feel that lugging type of vibration. I felt it Monday and Tuesday. Today going to work I didn't feel it much at all. Coming home from work I felt it again.

I've also had clunky shifting to go along with this, not consistently though.

2001, stock. I got it with 3200miles in March and now it has 8300. I have had a small oil leak from the plug area since about 4000 miles.
I put on a Raptor 1 week ago. I changed my oil and accidentally went with a synthetic blend of Bel Ray 10/40 1000 miles ago (made my leak worse). I normally use the 10/40 Dino oil. Replaced my plug with NGK 4000miles ago (haven't looked at it since) Air filter is original and kinda dirty. Went with an AGM battery on the 17th. I made sure to check my oil at every stop for gas on that 400 mile trip. Only had to add about 1/5th of a quart over the ride to keep the oil window full while holding the bike vertical. Bike idles nicely. Valves make a bit of noise, not too bad though (Have not been adjusted)

Any ideas?
Losing compression from the worsening oil leak?
Odd vibration from maybe loose motor mounts?
Dirty plug + dirty air filter messing things up?
Valves not happy?
Cam chain ready to wreak havoc?

Any insight would be appreciated. Let me know if there's something more specific I can say to help convey my problem.

Hmm. I did have my rear tire replaced at a car/MC repair shop about 800 miles ago which was about 10 days before this began. He adjusted it to plenty tighter than I had had it before. He said that was "closer to spec" than where I had it before. I think I adjusted it back out again afterwards because I wasn't comfortable with how quickly the rear was grabbing. But since riding around I've gotten used to it, doesn't feel too tight. I'll try loosening it though.

What are you referring to OF? I visit this site daily. If I didn't reply to anything for weeks at a time it might have been when I first started coming here. Sorry  

Oh, okay. I have seen exactly what OldFeller was talking about in some of the threads I have read. I do keep my own issues to my own thread. And I have made separate threads for separate/unrelated issues.

I definitely feel it more in my footpegs.

I'm definitely understating the severity of my leak with that sentence. Those 2 days I went through a 1/5 of a quart. Since I changed my oil only about 800 miles ago I've used an extra 1/2 of a quart, a good 450ml.
If I showed you a picture of the oil that's all over everything on my bike you guys might even tell me to park it, and that my oil leak isn't just in the plug cap.

But yeah, I'm vigilant about checking my oil and adding some as needed because of my leak.

Well that did stick out in my head, because I was wondering why a guy who had never worked on a Savage before knew what "closer to spec" was. He didn't say "Book spec" and I watched him for nearly an hour, I didn't see him thumbing through any manuals and I didn't see them in his work area. The guy has a real shop with 3 heavy duty car lifts and 1 motorcycle lift. I only went to a shop because I did not have the tools necessary to get my rear wheel off by myself to have the tire replaced. I've taken car tires off dozens of times, it's easy enough for anyone and only requires 2 tools essentially. But I'm new to the world of wrenching on a motorcycle. I need more tools! It's too late (almost 2am) for me to work on the bike tonight. But I will adjust the rear brake tomorrow and get back to you with the results.

Captain Obvious here    (sorry)

Check the tire pressures, and the front brake as well.  Maybe that shop didn't air it back up all the way when they replaced the tire?

Just grab the brake lever on the rear drum,, move it,, you should be able to feel the brake engage,if you cant, loosen it off.. Ride it, dont use the rear brake,, touch rear hub,, burn little fingers? Brake is dragging..

thers 2 ways to check it.