Wondering if Lucas will help?

Hello, I seem to of lost 3rd and 4th gear. After 25 mph it just seems like one big slip. It only catches once in awhile. I don't try to get it to catch though since I will get knock most of the time if I keep it in drive. Will Lucas help me? I have a feeling it won't. Sadly I have no other car atm so I am still driving the GN under these conditions. I put it in regular drive then at about 20 I'll shift it to 2nd and keep it there. I was told I may blow my motor but I am keeping an watchful eye on the scanmaster and the RPMs average at 2,500-2,700 at 30ish mph. If I gotta drive 40-45 MPH the RPMs avg at 3,000-3,400 RPMs. These are good numbers right? The motor should be ok as long as I am careful and I watch those RPMs correct? Thanks in advance for the help. Sadly I don't have the money for a race type of rebuild and don't really want a stock one. I like nothing but the best for this car.
Sounds like the governor spring popped out. It's a pretty easy fix, drop the pan, pull 4 more bolts for the governor housing thingy. I replaced the plastic speedo gear the last time this happened too.

TCI - GM 2004R / 200C
Well the car had a slight slip around the 40-45 mph range for a few years. I did have the pan dropped a couple weeks ago and had the filter changed. The filter wasn't clogged however I was told there was clutch material in the pan. The clutch plates or whatever they are called that you can see with the pan off look decent. I heard you can't see the ones for 3rd and 4th by just dropping the pan. With that info do you still think it could just be a spring? That sure would make my day if it was. I don't want to pay the guy a 2nd time to drop the pan and buy brand new fluid if that prob isn't the problem though.
With that info do you still think it could just be a spring?

Clearly something is broken and needs fixing. I'm no mechanic, but mine has spit them out twice before. It tachs out and barely shifts into 2nd. Feels like you can only go about 30 mph at a million rpm. Drop the pan, collect the fluid, should find spring material in the pan. Then replace the spring and pour the same fluid back in. Sorry, but if you have to pay someone else to work on your car, you have the wrong car to drive cheaply.
Oh I know these things are costly. I owned this car for 8 years and spent a good 15K on it. Worth every penny though in my eyes. I was just being pessimistic that the prob was going to be that easy of a fix. I just wish I had the $ now that I did the first few years I owned the car. Not gonna be able to rebuild the Trans anytime remotely soon. I need to get to work though so I still drive it and just keep it in 2nd. Am I still in danger of blowing the motor even though the RPMs I stated above don't really seem high? I know the Trans will keep getting worse if I keep driving but I don't want to jack up the motor.