I bought a 68 firebird 400 about 4 years ago. It is a great car but has some minor issues. The biggest issue that I just cant seem to solve is that it has run hot since the day I got it. It has an original 1968 400 block that has been refreshed so it runs like a clock except for the annoying tendancy to overheat. It has a 195 deg. thermostat and a clutch fan with the full cowl (I think). The first thing I did when I got it was replace the original radiator with a new 4-core. That got it to the point of semi-drivability if I drive it on cool days and baby it. Max speed on the highway is about 70. Anything faster and the temp creeps higher than I like (>210 deg.). If I do a jackrabbit start with a warm engine the temp instantly climbs 15 deg to 210+. I am pretty sure the fan is working. It turns when the engine is running. I am running 50/50 water to antifreeze so the mix should be ok. Is it possible that the coolant channels in the block are clogged up with junk? It did have the original radiator in it when I bought it and that old radioator was pretty nasty. Any ideas? I am getting kinda desperate... The car is pretty but it isnt much fun to drive.. A couple days ago I drove it down to the liquor store and the temp kinda got away from me. It was running 220 when I put my eyes back on the temp gauge. I got it home at 210-220 by coasting as much as possible, pulled in the drive and shut it down. I could smell some hot toasty rubber. Does anyone think I did damage???

Thanks a bunch in advance for any suggestions.

-Newby Birdman