Only have 1yr/6,000miles on an overhauled EFI 302. I've had to add up to two inches of antifreeze every 500 to 1,000 miles. No puddles on the floor. Nothing in the oil. I did have the radiator recrimped last winter, but there is no sign of antifreeze leaking. Any possibilities where it could be going? Any signs to look for if it is an internal leak?

 

internal leak? Check for antifreeze in your oil

usually it is oil in your rad tho, showing a blown head gasket

 

Or a bad head gasket sucking it out of the cooling system and blowing it out the tail pipe.
Look for compression gasses in the cooling system, does it build up pressure real fast and before it warms up?

 

I have noticed an excessive amount of moisture coming from the tailpipe when the motor is cold. I'll have to do some checking.

 

If you are putting water into your oil then chances are youd get compression in your radiator and after starting it your raiator hoses would be hard and you wouldnt be able to squeeze them or when the radiator cap is off it would blow water out of it. If it has plastic tanks on the radiator it might have a hairline crack and when it gets warm it will leak a little but when it cools down it wont.

 

might want to check the upper and lower hoses if they arent new they might be leaking when the motor gets hot. I was useing about a half a radiator full of coolant every 1000 miles. I had no visable leaks but was still leaking coolant, i replaced the hoses and i havent lost any more coolant.