Oil Leak into Cylinders

I recently tore off the head off this '92 Prelude H23A1 engine type due to a timing belt break which subsequently bent all of the valves. I had a valve job done by a local machine shop and as well I replaced the timing belt, serpentine belts, water pump, gaskets/seals, etc. The car now runs great, except I am getting blue smoke out of the exhaust. I know this is oil and when I remove the spark plugs I can see there is oil residue on the tips (inside of the cylinder) in all four cylinders. I know the oil can leak into the cylinder via bad piston rings, bad valve stem seals, or a bad head gasket. I also know I can perform a leak-down test in order to test the piston rings. Since all four cylinders are leaking, I am leaning towards a bad head gasket (bad from the manufacturer) or bad valve job (all seals are not working properly). Is there a way that I can test the valve stem seals for leaks while the head is still on the engine, or even if there is a way I can test them with the head off but without removing the valve assembly? Thank you.