I am currently in the process of swapping out my '73 hybrid motor (stuff from whatever) with a '81 ZX motor , 5 speed and 4.11 rear end. I am keeping carbs instead of EFI. I will be using header type system for exhaust w/2 1/4". my question is what is the necessity of the PCV and smog equipment? I have studied various posts and articles but, have not come up with a definitive solution as to remove or leave. What impacts can I look to incur if I remove smog system. I have looked at various PCV diagrams and have noticed some of you have installed a breather filter, I would have to have to assume that the PCV valve was left going to the block vent. Also is it necessary to leave the tank pressurizing system hooked up? I would greatly appreciate any feedback. -Tom - stranded in California City.