no crank no start on my 96 chevy tahoe

A good battery should read 12.4vdc minimum. If battery is good and still won't turn over, check all battery cables for corrosion and make sure they're tight. If all cables are ok, check for voltage at the starter solenoid small terminal. If voltage is present and still no crank, replace starter

Not always it some time weak leads wires too starter or coated in oil .clean them or replace.leads.

If timeing set too low for .on dell.at rate set for that year. Look at charts for setting. Then see if starter is faster.

Timeing must be set for 8 deg.b.f.t C. Not 10..8.is best. Dont guess.