If you hunt for a factory pair be careful. This (at the time) New Englander bought a set from someone in California. I forgot about CA emissions. These covers were for a '66 and have a depression in the left cover for an air pump. It bugged me at first, but now it's a conversation starter and it's staying.
I purchased these about 10 years ago from oldbuick. Max space inside for your rockers. Originals are the way to go.
Well, I bought a set off of a member here and am happy; - he gave me a deal I couldn't refuse and even with exchange it worked out to less than a repopped new set. I'm going to mount them up next week; - and yes, the PCV is straight whereas my 66 was originally angled. I don't really care; - sure, a purist would, and if anything it'll be a test to the various "entourages" of "car guys" that come by and look at the car in the next show that I do; - if I do one. A purist might also note that the bucket seats I'll have installed are not the right ones either; - I have a 65 set and not the proper "strato-buckets". 99% of the population wouldn't know the difference even if it was spelled out to them on paper, and nor would they care.
Mooneyes I had fit over my Telesco rockers no problem... The real problem was I couldn't get those things to seal without leaking to save my life the bolt hole shape sucked, and gasket surface was less than optimal. They were a real PITA