I have a 4.2L with a throttle carb injector from a chevy 4.3 swap. Well my motor started knocking and my passenger side motor mount bracket to block broke. Anyways, I bought a new block from a jeep grave yard thinking to just swap everything over. Problem is that i found out the block is 4.2L EF3235444 block casting number with a 4.0 head 0630 cast number on head. My question is what should i do? I dont know if i should take the head off my existing block thats knocking and put it on the new purchased motor and swap everything over being that I have all necessary parts or find a way to use the 4.0 head thats already on the purchase motor, but i wouldnt know where to start!? The head on the new 4.2l motor does not have the intake manifold. Your help would be greatly appreciated.