I have a 1987 honda civic wagonvan 4wd that won't pass emissions. It has a recondition head and carb. The previous owner seized the cam to the valve rockers prior to the reconditioned head. The motor has poor compression in cylinder 1 and 4. Around 60 psi . #2 and 3 are around 165 psi. I have installed new rings and no change is noticed. The motor hesitates when you tromp the gas and puffs smoke out the exhaust. After all the troubleshooting I can only think the block is worn out. The car has only 120k miles. If anyone has any suggestions they would be greatly appreciated. Thank you