CAMSHAFT SNAPPED WHILE DRIVING

I have a 91 FI 2.4 . Ok so I was driving home one day on the freeway cruising at about 70mph when all of a sudden my truck started missing bad and had a huge loss of power. I barely made it home. I checked plugs wires cap rotor timing and finally when I did a compression check noticed very little compression in the #3 & #4 cylinders. I removed the valve cover and upon inspection noticed my CAMSHAFT had sheared in half right after the center cam journal...soooo I replaced the cam with what I know to be the same CAMSHAFT out of a FI truck, and my truck still sounds horrible...checked compression around 170 at each cylinder new wires plugs redid the timing twice because I realised I was actually off a couple teeth the first time. Distributor is stabbed right firing order is right. I figured id try asking for advice before I pull the head or even the engine.....thank you in advance.

I used the original cam sprocket with the cam i found at the junk yard is it possible that timing marks may be different for different years?