no compression

replaced head gasket, (leaking externally) as well as timing chain but only as preventive maint. now it will crank, but no compression. have all the essentials(spark, fuel, etc.) anyone encounter this????

when you replaced the timing chain, did you line the gears up properly, if they're 180 off, that would cause no compression.

yes the gears are lined up along with the crank.

I would recheck the timing to make sure everything is lined up properly. Even though the gears were lined up along with the crank you may have had it out of time before you tore it apart. They can be quite funky sometimes and will fool you. I am not demeaning your mechanical expertise it's just that it can happen to anyone. I speak from experience!

I second the timing.
I'm sure you know that camshaft makes two complete revolutions (Two 360 degrees) per one complete revolution of cranshaft (One 360 degrees).
Even though the camshaft is aligned with the crankshaft, it might be that either the camshaft or crankshaft was turned and so they are 180 degrees Off. When it does happen, the exhaust valve will open when the piston is in compression mode and so you will not get any compression reading because the compressed air/fuel mixture is going to the exhaust.

I've done that while I was fixing our vehicles. I have to remove the timing chain again and turn the camshaft sprocket 180 degrees and then put back the timing chain and it solved the no compression problem.