Hey Mechanics, What Do You Think?

Question

1972 Chevelle 350.

I replaced my Cylinder Heads but used the same push rods, lifters, rocker arms etc... Anyway, since that time, my friends and I installed all the new parts and all that and now, we notice a big compression loss in half my cylinders. When we replaced the heads and gaskets, that was because the head gasket was blown and coolant was mixing with oil. However, the car was not driven at all like that at all and has not been. As soon as we spotted that, got old oil out, replaced those, and filled up with new oil.

Anyway, we checked the compression. Cylinder 1-3 has really good compression (normal -150), and the others are low ranging from 60-90. These heads are brand new and it was not knocking so I doubt they are bent/burned or whatnot. The pushrods are straight, and lifters are pumping and once again, the car has not been driven at all. Started, then shut off after about 15 seconds if that. Anyway, when we checked the compression and found out it is low, we found

Answer 1

Question is this:

"If they are too tight, would that cause compression loss?"

Answer is this:  Yes.  If they're too tight, the VALVES ARE ALWAYS OPEN.

Answer 2

As said above, you most likely need to adjust your valves.  

Also, if it has only been run for 15 seconds, I imagine that the hydraulic lifters have bled off during the head change and need to be pumped up.  Run the engine for a few minutes, build up pressure and then check.  While you're at it, recheck your head bolt torque.

Answer 3

I would surely would loosen off on all of them,then i would tighten al of the head bolts up again and like you said start it back up and tighten them up until they stop ticking One of the value's could have been hung up and causing it to loose compressionor it could have been holden the head up just enough to keep it from sealing.Hope fully you didn't smash the new head gasket.