Just installed a 312 head and am having cooling problems. The head was boiled and checked for cracks, it passed the test. Now the head is hot while the other head is cool. Coolant was boiling.
The head that is hot is on the left side (driver side)

Just one head was removed? For what reason? Was it hot before? The coolant was boiling but one head was cool?

Need more information but it sounds like something went awry during installation.

Thanks for the get back.
Had to replace lifters, cam etc because of lifters snapping in two. After we took the engine apart we noticed cracked head, found one on ebay. Had it boiled and checked for cracks, it was good to go.
Started the half hour break in sequence with rad cap off and about 15 minutes in the operation, the water blew out of the rad and gained altitude of 6 to 8 feet. Let engine cool down, put on rad cap this time, about 10 minutes in, the gauge hardly moved. Checked rad, it was cool. Some pressure was building up because the rad cap was leaking and the bottom hose was leaking a little.
Now, felt the left head.......very hot, felt the right head , cool to touch. And the gauge, an after market mechanical one was at maybe 110 degrees after 10 minutes of 1500 to 2000 RPM
Why the heat difference ?, why the boiling over ? Can you help ?
Thanks,
Tim in Florida

My guess is that the head gasket is backwards.  Is the square corner of the gasket sticking out from under the upper front corner of the head, or the rear upper corner.  It has to be under the front corner.

John - "The Hoosier Hurricane"

John,
Square corner of head gasket is facing front of engine.
Timing is at +8 degrees.
No shroud on fan.

John,
One more thing.
We only drilled an extra hole for cooling, in each head. FelPro says to drill two holes per head.
Is this a problem
Tim
Florida Ford Fan

Tim:
I don't think the lack of the extra drilled hole is a problem.  Look at how little water could flow through them.  I think they are intended as an afterthought by gasket companies to prevent air pockets in that area.  I'm at a loss now concerning the heat problem.  Oh, is it possible there is a freeze plug in the front water passage into the intake because a former right head was used on the left side and the freeze plug was not removed?  Or if a former left head gets on the right side and the bushing for the water temp sender is still in place providing a very small hole for water flow?  Could someone have welded up the trapezoid shaped water passage for some reason in the end of the head you bought?  Sorry I don't have a definitive answer, that why I'm making these guesses.   

John - "The Hoosier Hurricane"

Hey John,
Thanks for trying.
We're going to pull the head and see what we can see.
I'll let you know what we find,
Again, THANKS !!!
Florida Ford Fan (FFF)

Tim:
Another thought came to me in the middle of the night.  Since the timing cover has been off, could something be blocking the hole into the front of the block, like maybe a gasket that didn't get the hole punched out?

John - "The Hoosier Hurricane"

John,
We'll look into that possibility about a gasket without a hole completly punched out.
Just like the "hanging chad" during the Bush/Gore election. 

Tim in Florida