i have an 82 fire bird that has a progressive heating problem.  400 sbc with 142 weind blower. radiator is new 2 row alluminum, has new waterpump, i added red line waterwetter. i have an electric fan that efficiently covers 85% of the radiator. it pulls air very well. air dam on car is in very good shape. timing is correct, carb is not running lean. exhaust is new 3 inch. checked for blown head gasket, changed thermostat, have used large and small pulley on waterpump. temp rises slowly to about 230-240 without boil over. engine is bored 30 over. heads have mild popcket port work. coolant is 50-50 mix. temp is perfect in wintertime. about 180-190.temp sending unit is new. i will check the gauge against a mechanical gauge next. but i am pretty certain the electric gauge is ok.

Too much engine, not enough radiator. If you can't fit a larger radiator, add an oil cooler with a thermostatic bypass to shut flow thru the cooler off when not needed. This should take 15-20 degrees off on a hot day.

Bogie

i like that idea. i will look into that. thanks for the response.  

my problem was a bad temp. gauge. i tried a mechanical one and the temp was fine. never went over 200 degrees. thanks for your input. seeyaby.  

That's a good catch, while I always check gauge accuracy in such situations, however, I find that a faulty gauge/sender is a fairly infrequent occurance and usually the solution is one or more of the expensive choices.

I like it when we get lucky and it doesn't "cost-an-arm-and-a-leg" to resolve a problem.

Bogie

I was really glad it didnt cost any more than the 15 dollars i spent on the gauge to check it with. Seems like the cost to have fun never ends with fun. glad to have you guys out ther for help. I have been working with cars for about 20 years now and I still find new problems everday even with old cars. They arent always text book fixes. Thanks for the help.  

I realize you already found your problem, but for the sake of anybody else:
A buddy of mine had a 396 he just rebuilt for his '67 Chevelle.  It constantly ran over 220 and he couldn't figure it out. Finally he realized the fact that he was running underdrive pulleys was his problem.  He switched back to factory pulleys and it dropped back to 190.