Possible Flywheel?
 

94 Full size blazer with an auomating. I think I may have an flyweel craked, cracking, or missing teeth/tooth. It startes a few weeks ago with an intermittant knocking sound, but seemd like more of a clicking or tapping sound that would stop when I out it in N. Today it suddenly got louder and did it near constantly and then when I got home and hit the starter it spun and then sounded like a dead spot or the starter missed. 1. Is it the flywheel? 2. How do I check and replace if it is? Thanks in advance for any assistance.

Definitely sounds like the flywheel could be at fault. You can check the teeth on the flywheel by removing the dust cover on the transmission. It'll be held on with 4-6 bolts and it will be directly between the engine oil pan and the transmission oil pan.

Checking for a cracked flexplate (flywheel for an automatic) is a bit more difficult. If you have large cracks, you should be able to see them when you take the dust cover off, but typically they crack around the center where it bolts to the crankshaft on the engine.

To replace this, get yourself some 4-6" long bolts that are the same thread as the bolts holding the transmission to the engine. I can't remember if they are still standard threads or metric threads in your application, but just remove one of them and head to the hardware store to find the proper bolts. The longer bolts will allow you to disconnect the torque converter, unbolt the transmission, then just slide it straight back to get at the flexplate to crank bolts.

Thanks for the advice, I'll look ino it this week.