Probably not, as long as it mimics the oe stuff. If the oe cap were vented you might want to get a vented one for yours. Did your ride have a charcoal canister when new? If so, they will probably look for it, as well as having the carb hooked to it. They will probably just grab the vent line to the carb, if it is needed and pull on it. I had a open element air cleaner, just clamped the hose to it to get thru. There is a good chance that they will have no clue as to what your car came with, so you might want to just go and see what happens. When I bought my Fairlane into AZ I had to take it and the vin verified, they did not know where it was located so they just let it go.
I used to live a few miles form the proving grounds. I was in Mesa, the Red Mountain park was right behind my house. If you ever need a trans guy my buddy is on the end of Meridan. Guy does fantastic work.
Not that it is any of my business but have you thought about just getting collectors insurance? Not only have the benefit of having full coverage but it would also mean you could avoid the Sniffer crap. I know everybody thinks they will be able to drive there car year round in the "Valley of the Sun" but brother the summer is brutal. If you have another vehicle with a/c that whole "I am going to drive my hot rod everyday thing" will go out the window first time you drive the car with a/c. And do not forget that Queen Creek/AJ gets bombed with Snow Birds every year and with all the old folks that should not be driving anymore that area can be a bit of a hazard to drive your classic car in. I believe Grundy offers an unlimited mileage type of deal.
Have you been out to Tortilla Flats yet? Bit of a tourist trap, but in the summer it is not to crowded. Another nice ride is out thru Globe and then up thru the Salt River Canyon.
