The statement "when I stop it lets out water" bothers me a bit. On a "perfectly" restored Maverick it should let out NO fluid (water, transmission fluid, oil, etc). Where is it letting this water out? I have a newly rebuilt 250 in my garage (recently replaced with a 302) and it would burn you out of the drivers seat with heat.

You mentioned that you had all of the cores cleaned, but did you check the hoses to make sure they were clear? I can attest to quite a few friends that have had thier heating system flushed, worked for awhile, but only to have the cores plugged again with debris that the last "flushing" loosened up, but did not get completely out.

Do you have a thermostat on the engine? If not then I'd get one as the engine will never come up to temp in the winter. Also, do you have a water temp gauge installed? They are usually pretty inexpensive and well worth the money. How did this engine run in the summer? Did it run hot or what?

Let us know as we can definitely help you on this one!

Regards,
Tracy
'76 Mav