A compression test might help. usually when a chain is off, compression reading will be all over the map. some way high, and some lower. if you find all pretty equal, I would bet chain is fine. I don't think I ever did a chain on a 4.0 for jump timing. If you turn cam sensor housing to get it running, how does it sound? if you have it running, get a vacuum reading, jumped chain will also have low vacuum.usually around 20 in. of vacuum is normal. Do you have access to a scan tool to read the sensors? timing is controlled by the PCM, cam sensor just fires / sync's the injectors. did you set TDC feeling the piston or go by the balancer? maybe the balancer mark is off?