1996 chevy silverado v8 4.3 won't crank. Replaced

Check the fuel pressure. Should be 55 psi. Here are a few possibilities
https://www.justanswer.com/chevy/b6nmz-1998-silverado-55-psi-fuel-pressure-key-on-lots.html#:~:text=1998%20Silverado.%20Has%2055%20psi%20fuel%20pressure%20with,on%2C%20lots%20of%20spark%2C%20cranks%20but%20won%27t%20start.

Starter is good,battery and connection,Cap is good no cracks.

Check distributor I have a 93 1500 pull cap and trun engine over watch the shaft if nothing turn truck off and check free play on rotor bug shaft

why?

Check spark plugs, leads, distributor cap & rotor arm, fuel pump, fuel filter, coil pack(s), relays, replace any items that are suspect IE Fuel filter which has probably not been changed since new even though they should be changed on all vehicles every 18 months, all of this can be done at home & will save you a lot of bucks in mechanic/garage fees,

could be a number of things. could be as simple as a clogged fuel filter, plugs and wires maybe

Have you checked for a broken timing chain, that would be the next step. Make sure number one cylinder is up on compression stroke when the timing mark is on 0 degrees BTDC on the crank pulley. Pull the plug and feel the pressure as it nears TDC.

Same problem here, found break in wiring harness at cross-member behind cab. did have bed removed for easy access. Ground wire guilty party.

you said you repl dist cap that means you don't have a crank sensor you have electronic ing module. remove your elec ing module have it tested most auto parts stores could test your module, or check your coil at the neg terminal. should have power. if not you lost your primary volt from your batt.your secondary power is coming from your electronic ing module from the module to the pos terminal on the coil, when the eng cranks,from the coil to the dist cap , from the dist cap center to the rotor then out to the plugs,this all happen pervided the timing belt or timing chain is ok. the cumbustion chainber needs 3 things , thats fuel, air, and spark.

I would check a few things:
Load test the battery. If its got any age on it at all, this could be the culprit.
Test the starter.
Check for loose connections at the distributor cap. Make sure the rotor in the cap is seated and that the cap is properly seated.
Check for loose connections on the battery, the starter and make sure you have fuel pressure on the injector rails (key on, detent the shrader valve .. you should get fuel).