Horsepower Loss / Cooling Problem

[A Wild Neg]

I own a 83 Mustang 5.0 all done. I bought it like this, and the owner before me had a cooling problem. It would run at 220 + temp and he had all the goodies to try keeping it cool.
The first thing I did, was replace the radiator from the one he had to a large alum. one. I put in an high temp electric fan which was controlled by the temp, but I soon changed that to a toggle switch. The car is basically a street legal strip car. So to run hot isn't to bad, but at 220 is pretty hot. The next thing I tried, was taking the thermastat out. I put in a 180 after that had no effect. Then finally I adjusted the timing, found that the intake was loose, and now it runs about 200. Which is great. It keeps a large large amount of power even while its been running @ 200 temp for 15 minutes.
The problem comes afterword. I'm not sure what else could be causing it. After the car runs for 20 minutes of just cruizing around town, I start to loose an enourmous amount of power. It's still got alot, and powerful, but I can tell from the time I took it down the street to cruizing around town 20 minutes later, that their is power missing. So my guess is a heating problem somewhere. Something gets hot, and causes my power decrease? Any other ideas? What should I replace to keep it cool?
I'm going to order a double radiator / 2 electric fans to keep the colant cool which really isn't a issue anymore (But to be safe). I'm going to go from 5 qt oil pan to a 8 qt and get a super oil cooler. I'm going to then get a custom ram air kit mainly for the cool dense air from outside the car this way the carb isn't getting this hot air thats inside the engine compartment. Is there anything else anyone can think of or possibly check that could be doing this and I need to replace? Thanks!


- Kevin (A Wild Neg)