Not running right

[spyder1438]

I have an 87 ranger 2.9 manual that I picked up not running told it only needed a high pressure pump. Come to find out motor was seized. Swapped known good running and driving motor from an 86 that the trans went out in. Engine runs but bucks and jerks anytime you try and drive, and when parked and revving it just wants to die. At times it will rev up fully if you gradually increase throttle other times it wont. I have replaced the o2, map, tps, air temp sensor, TFI, ignition coil, and coolant temp sensor also ported the upper and lower intake where they meet. I am at a loss and beating my head against a wall any help is greatly appreciated.