Coming from intake behind distributor but if I remember correctly coolant don't flow through intake

 

Depends on which engine. If 335 series, could be over at thermostat housing just migrating / following along the seam at the base of intake on top of the China wall.

 

351m

 

It could be leaking from the top rad hose at the housing, running down to follow the seam.

There is a rectangular hole into the water jacket covered by the head gasket up near the intake manifold, but is not likely.

 

My approach would be to thoroughly clean the area (I'm talking super clean). Let the engine go stone cold. Then pressurize the coolant system and watch. Fluid will run along seams and crevices... this is where the ready diagnosis come in

 

If i may, I'll share my cooling system issue / solution for my AMC 304 V-8.
Similar to a fan clutch failure, the engine did well for cooling until climbing up long grades into the mountains, then the temperature would steadily climb until it overheated at 240 degrees, and belched collant out the overflow.

Anyways, long story short, I finally came across a forum thread where a professional mechanic said this:
When you have exhausted all means of solving the issue, there are Two remaining sources.
1. Stretched head bolts.
2. a crack in either block or heads that opens up at a specific temperature.

Like TBear mentioned, super clean the engine, which I did and upon looking closely, guess what ?
I discovered a lower head bolt with the bolt-head missing !! _ _ _ that pro mechanic knew what he was talking about.
Doing a cold cooling system pressure test, the system held pressure.
Once my engine reached approximately 230-degrees, the head allowed combustion pressure to Pressurize the cooling system.

So, my thought here, if gaskets and hoses aren't leaking, there is the possibility of a stretched or compromised upper head bolt.
Just a thought. Probably not in your case since you haven't mentioned any over-heating.

I am a lifelong user / believer in Gasgacinch sealer now sold by Edelbrock.
If using an existing hose to nipple, I will take my pocket knife and carefully scrape the inside surface of the hose to clean rubber, then apply Gasgacinch to the hose and nipple, then install hose clamp and let sit overnight for the sealer to 'set' before topping off with coolant.
Also, in 2023, my 385 series 429 sprung a leak at the top of the aluminum timing cover-to-block face.
I ordered a new timing cover from Summit and sealed it with Gasgacinch. No leaks since.

Good luck with the LEAK, and let us know what solved your problem.