In North Carolina cars less than 35 years old still have to have emission check. My guy checks to make sure parts are there but does not do the sniffer test, just have to have the parts. So minus a cat converter could or should fail inspection. Now in NC your car inspection is tied to your tag renewal, so not inspection, no tag.

There is a lot of stuf on this on the Net by people that have done research in the area.  Below are just a couple of link with some of the latest information on the subject.  Things change so you need to look at the latest stuff not items that were 5 or 10 years old.  In this case however there has not been a lot of change except the modern oils are a little worst maybe.

I use Valvoline VR1 20W50 on my '64. CCasey2011-06-27 09:58:09

The cat convertor has been taken out of my '82 and made into true duals (check engine light bulb also removed behind dash), ending with Flowmasters' at the tips. Florida has no inspections. Better performance (even better since the Exxon station nearby has a NON-ethanol pump at 90 octane). So, with that being said, it never changed my preference on oil at all...with or without the cat convertor. I had always used, and still use, Valvoline's synthetic blend 10W40. Specifically designed for cars over 75,000 miles on the clock. No leaks.

|UPDATED|6/26/2015 4:04:52 AM (AZT)|/UPDATED|

Ive been told by mechanics for engine break in oil., to use a good grade regular Dino oil for 2000 miles, then switch to full synthetic   .  In my BB,  I switched to Valvoline full Synthetic 10 w 30  from Mobil 1 full synthetic as the Valvoline beats the pants off in the independent 4 ball wear scar test on the major brands --- Valvoline is tied with Amsoil  on this test as the winner and cheaper to buy .

that's what I use     reg oil with lucas     dwa

Mobil 5W/30W high mileage/older engine oil.