No compression #3

I have run compression test on this new to me engine, dry and with oil. Number three has no compression, but two and four are ok. Is this likely to be a cracked head, and/or just a blown head gasket?.

NO compression? Bent valve.

I plan to remove intake/exhaust, bust out a spark plug, braze into it an air fitting.
When I apply air pressure, I may: hear an air leak out of intake or exhaust port (bent/broken valve), or air eruption out the radiator (head gasket) or air noise from the oil fill hole in the valve cover (hole in piston). Keeping fingers crossed for head gasket.
On second thought, I will just fill radiator with water and spin, bubbles, head gasket.

No bubbles in the radiator, going to the 4.3 GM engine

Scrap that, I pulled the head, you were dead on in the ball park. Corroded stuck intake valve. As is, valves all look good, have the seats dressed, lap the valves in and go with a head set.
When this engine gets tired, another 100.000 miles (?), I will have the 4.3 set up [200 horses carbed (on it), HEI distributor (in it)], and a shift kit in the transmission.
I started this post hoping for an answer. This is about the truck here: http://www.mazdabscene.com/threads/141206
Where I have gotten not a single anything, figured adding this there would net the same results. Thanks

Ground the valves, lapped them in. New head set came in Saturday, assembled it and got it on. 150 lbs. compression, now to fabricate the carb intake. Got the bolt up face plated cut and drilled today. Now the tubes, carb base plate, plenum and assembly. Going with the GM Dual jet again (also called the Vera jet, half a quadrajet). Then engineer the distributor and bud n' bud.