okay guy's, check this out, i picked up a 1973 3/4 ton with a 390 or 360 don't know for sure yet, i'm just going thru the motions to get it running at least half assed right. so the coil was mounted on the front of the drivers side head instead of on top of the manifold, when i pulled it to to put a fuel pressure reg. in it's place i had coolant pouring out the bolt hole on the front of the head. now it's been almost 20 years since i had an FE motor but ,{ My ex got the last one truck and all } i don't remember having coolant coming out that bolt hole.this truck has been thru it if you know what i mean, but even running like **** it still ran ok. far as i can tell it;s a stock 390 with the stock 4 bbl intake, {which is why i'm guessing it's a 390} someone stuck an edelbrock carb on it and a pertronix igniter in the dizzy, although half assed both and a sorry effin carquest elec. fuel pump, which lasted long enough to leave me on the side of the road. i have since replaced it with a mechanical pump and that is the reason for the fuel pressure regulator. i drove this truck 2 day's ago around town making stops here and there in 90% heat no problems what so ever with the cooling system , oil is clean no milk or froth, nothing showing on the plugs, so what's up???? i've never heard of an FE cracking a head before the block but i can't think of any other explanation. what am i missing here.
Know what i did? moved the coil back up on the mani. mounted my fuel pressure reg. in the same hole the coil was in put a little rtv on the bolt threads and im calling it good for now,haven't fired it up yet, but we'll see in the morning.

 

Could be that previous owner forced a bolt into that hole that was too long. Or there was a bolt rusted in and they drilled it out and went too far.

I wouldn't worry about it TOO much, the water jacket in the head is right behind the bolt hole.

 

i fired it up this morning and like you said nothing to worry about no leaks. thank you for the reply, it's always nice to have another mind working the problems

 

Ok,
i have seen this before.
i had rebuilt a 352 for a 58 tbird.

The head had a hole, a round hole that was worn through between the water passage side and exhaust side in the head. The hole was about 5/16 to 3/8 in size and actually looked like it belonged there.

I had the same issue you had as far as the water coming from the head bolt.

When i fired up the motor i would loose all my coolant out the tailpipe. This can also happen between the intake and water passage in the head as well. Took me a couple weeks to figure it out. I used a laser temperature gauge fired at each one of the exhaust manifold outlets and my number one cylinder was way cooler than the rest. Further searching revealed the hole in the head.

I figured it was a water venturi effect. Water erosion from a very slight casting flash that created a tiny water vortex in that part of the head....a water drill... It was a perfect hole. Hard to believe it didnt belong there.

Watch out for your coolant levels. Use a laser temp gauge and check your exhaust manifold port temps.