Are PCV needed?

I'm sold on PCV valves, I've now been running a PCV valve for almost two months now. I also replaced the main rear seal that was leaking, may or may not been caused by not running the PCV during break in. The motor did set complete and ready foor install for over a year while I did the rear end swap and front end work. Seal may have dried out and burnt on cam break in???

With the PCV now installed I have no oil leaking from the valve covers, breather. I still have a very slight rear seal leak, maybe a drop per day or two, damn it! It was tough getting the pan back on without the pan radius gaskets tabs pulling out.....maybe too much ATV! The rings have now seated better also, was getting smoke out of the right side when romped on and now appears to be gone. Car seems to be getting great mileage, can't measure yet, speedo is not working. Ordered cable and it showed up with the smaller female connection (didn't measure, maybe 5/8"), wrong, need the 7/8 end.

Thanks again everyone for the input!