Could my 340 block be filled?

No fire,the simplest of test lights will track down your problem.
Ground alligator clip,probe pos side of coil with key on. Should light.
Move ground clip to pos post on battery,probe neg side of coil. Now crank engine. Light should blink.

Do i need to mention, verify that test light actually works before and during test procedures? There is nothing worse than an intermittent tester to screw with your diagnosis. Garbage testers yield questionable results.