1997 Pontiac Grand Am wont start

In aug the radiator went and I replaced it, found I had blown the head gasket, put in steel seal according to the manufactors directions and replaced spark plugs. Started ran, next day would not start, replaced coils and checked ignition module which was fine. Still didin't work. Replaced crank position sensor and oxygen sensor, nothing. Replaced computer with a pre-flashed computer and did the lock relearning, still nothing. Now my son says he noticed that the tackometer (sp?) Doesn't move when he tries to start it. Is this something else I should be looking at? I"m at wits end. I'm on disability, can't afford a new car nor a service station to fix it. Please help!

Thank you in advance.