Hello my name is Brodie I'm new here and am looking for some advice to fix my overheating issues. This will be a long post since I've been fighting this issue for about a year now. I have a 94 originally V6/AODE car that I have swapped a carburated 347 stroker that makes 475hp and 450lb ft at the crank along with a AOD that has the one peice input shaft kit that I can use a C6 style converter with along with a transgo shift kit. The converter is a 9inch~4500 stall along with a swapping the 7.5" rear end to an 8.8" with 3.73 gears however they will soon be 4.56s. I also have a champion 2 core that is slightly thicker than stock but is advertised as a direct replacement radiator that I am using the stock electric fan setup on. For a trans cooler I run through the radiator and then into an external cooler and back to the trans, I have never seen my trans Temps get over 190 even after a 45 minute cruise. Back when this car still had the V6 I had the radiator start leaking and that is when I put the champion one in. After that my water Temps were rarely over 185. Even in the 115 degree heat. Once I swapped in the 347 and AOD I started having heat issues. This motor and accessories setup has been proven in an old circle track car. I could run 50 laps on a 3/8 mile oval and not get over 200 degrees. However as soon as I got the car running and driving I went for a cruise and everything was working perfectly with water temps at 190 until I Reved it over about 5000 rpm and it pushed a ton of water out and spiked the gauge to almost 260. After pulling over and letting it cool down for 20-30mins I headed back home and it was fine again sitting steady at 190. And every time I drove it the same thing would happen cruise it and it would sit happily at 190, give it any rpm and it would meltdown. I've tried everything. I know it wasn't headgaskets, I've changed them twice. Just to be sure and done multiple chemical test to make sure there were no combustion gasses in the coolant. I've tried 160,180 and cut out thermostats with no change. I've tried jetting, timing, even put 110vp in it to make sure it wasn't detonation. The weirdest thing to me is that when it does meltdown I can put my hand on the radiator and it will be cool to the touch my guess is 60-70 degrees. However the cylinder head will measure 240+ with a temp gun. Ive tried running it without the radiator cap on and it looks like there's plenty of water flow. I've recently put an expansion tank in between my upper radiator hose to make sure I'm getting all the air out of the system. Which only seemed to slow down the meltdown. At this point I'm seriously thinking about switching to methanol. I'm out of ideas and need serious help, I'll post some pictures and videos in the attachments if I can. Thanks In advance for any advice and for reading this far.