In desparate need of early model 71 dart fuel cap

My car is '70 model year, but it is a California car so has the EEC. I have the cap as described in post #27... visually identical to the one on the left in post #5.

As described above, it takes two turns to release the cap, but that could also be described as two motions for a total turn of about 270 degrees (3/4 of a full turn) due to the two sets of latches holding the cap into the filler tube.

So... question: Since I am removing all of the EEC equipment from my car (yes, I have checked with local regulations first, keeping PCV of course), it sounds like I should replace my filler tube with the vented style with vented cap... correct? And I hope this is the more common one to find?

Also, my cap is chrome with black plastic handle. I have been assuming this was aftermarket. Or is that how the factory non-vented caps were?