Baystate Jeepers

As you know I broke the motor in Mona. Hears what Ive done so far , maybe someone has an idea. Its a 74 engine block with a modified 92 XJ cylinder head, Milled 60k , 100k off the valve spring seats ,water heated manifold,tube exhaust. When I checked the fluids and serviced her after Toys for tots run in Dec, The radiator was like half empty. So a wed night I went to a Jeep meet and home 4 degrees that night. It ran fine both ways 4 maybe 5 mile trip. Moved her the other day so I could do a tune up on the Cruck and checked the rad once again. It was over half gone and into the oil pan. Nothing coming out the exhaust. I filled the rad and put a psi test on it. I have a 16lb cap , went to 20 psi. The gauge was falling slowly but steady. I pulled the plugs and they are durty from the season but not water fouled. With the psi at 20 I remotely turned the engine over , nothing (coolant) came out of the spark plug holes. Pulled the valve cover and turned over the motor. Everything was Fluxing as normal other than all the milky stuff. Pulled the intake and exhaust and Cyl. head. Cleaned the head and brought it to a shop to be magnafluxed . Should know today or mon. The head is casting 7120 not 0331 from which Ive read had a cracking issue. Any have info on this year head (92) having issues. I looked at the pistons and again there is no signs of coolant in the cylinders. Looked at every cyl. wall not that you can see a micro crack but for the psi to fall as steady as it did. So Im either hoping its just a bad head gasket , cracked head unless you might have another reason for coolant getting into the pan. Im planning to remove the engine block also and while Im still looking for the reason I going to finish the engine to speck. Im going 30k over and zero deck the block for another 30 ponys ! Its only logical , Any Ideas Ive missed or you know someone that found that ???? Thank God for winter ! Come on SNOW , I need the income. FjR68