i have an 85 z28 that came with a 305. i bought it for 300 dollars with a cracked block. i removed block bought a factory crate engine from atk motorsports. i put edelbrock intake, carb, a new water pump, hoses, gaskets. when i reinstalled motor i noticed it was running hot so i bought a bigger 4 core radiator for the car. my problem did not get solved so i bought all new equipment such as cap gauge thermostat water neck and i already had an aftermarket crank driven fan. the problem was still there. i heard about problems with these engines that others had so my dad was gracious enough to let me try his sooped up 350. well once again i still had problems. i adjusted the timing countless times timed it with the light and everything. so i bought a 16" reversible fan and mounted it on the outside of radiator to see if that would help the situation. so i pulled out the thermostat and still had problems. the shroud is fine and sitting good idont know what else to do if any one can help please do my email is noonespecial72883@yahoo.com please help

 

Can you get an underbonnet pic up on the site ? get as much of the radiator into the pic as you can.

 

Check Your carb jetting. Your exhaust pipe should have a nice tan color to it. If it's black........too rich, If it's white.......too lean. Also, You stated that You had checked the timing countless times, well it still may be too advanced, try retarding a little and see if that helps. It's going to be a little of both probably.

 

Put the thermostat back in. Replace it with a new one, your could be defective. That gives the water in the rad time to cool. How hot is it getting? Is the air deflector still under the car?

 

try an electric water pump and double check all the connections