installed vortex 5 7 engine in 1999 Yukon GMC on 1999 GMC Yukon

installed vortex 5.7 engine ran good on highway for 15 minutes then it went dead I replaced the battery towed it home now it misfires trying to set the timing continues to misfire any suggestions

Asked by for the 1999 GMC Yukon
Check the basics, electrical connections vacuum hoses ect..... Your truck has On Board Diagnostics (OBD2).
Is the Check Engine /Service Engine Soon light on? If so there will be information stored in the computer of your car which will be key in diagnosing whats wrong. A professional grade scan tool allows key engine sensors to be analyzed without having to do intrusive testing at each sensor on the engine. Engine needs fuel, spark and mechanical integrity to run. Need to figure which one you are missing.
Autozone have some popular workshop manuals for free on line once you register (for free) on their website or there is a company that independent auto repair shops "buy" their information from that offer a very reasonable service to do it yourselvers. You can get a one week subscription or year subscription very cheap. The information is year make and model specific repair procedures, service bulletins, component locations, wiring diagrams ect.... great quality information same as the professionals have ,much better than generic workshop manuals from parts stores, much cheaper than the factory manual try
and get an online repair manual subscription.