4.3 cranks but no start

Make sure battery has a full charge. Have helper crank it while you visually check for spark at the plugs. Have you visually checked for spark? Have you checked fuel pressure, usually 60--66 psi, key on engine off. Any applicable trouble codes? I saw what you replaced, don't know what testing you've done?

You need to follow troubleshooting procedure not just replace parts by guessing, that gets to be expensive and not solve the original problem, sometimes making it worse because you might do something wrong or use a defective part and now you have more issues than when you started. Make sure you have a good fully charged battery, check battery voltage, it should be minimum 12.4.If battery is ok, spray some quick start in the throttle body to see if it'll start for a bit, if it does, it means it's not getting fuel past the injectors but at least it eliminates spark or timing issue. Check fuel filter,check fuel pressure. If fuel is ok, check crank shaft sensor. If still doesn't start with quick start, check spark at spark plugs. If spark is ok and on time, meaning spark is on when TDC. check timing firing order, If timing and firing order is ok, do a compression test.