1998 1500 5.9 no start

[jeffn84]

I purchased a 1998 Ram 1500 5.9l 277000 miles and a 4" lift non running. It would crank but no fuel or spark. I changed the crank sensor (with help from other threads) and I have fuel and spark but still not starting. it has new plugs, wires, cap, rotor, and pickup coil. the compression is good and I have checked all the relays. The guy I bought it from says he had the timing chain replaced and it ran for a while but struggled going up hills and one day it died while he was driving it and would not start. Could a clogged Cat keep it from starting?

Thanks
Jeff
P.S. I have always been a GM guy so my knowledge is limited when it comes to Dodge.