Yes, positive on the right and negative on the left if your looking a the battery installed and facing the engine. The pic is correct. I was thinking of going back to the original side post look sometime since what I have installed now is incorrect and I'll need a new battery in the next year or two. Getting close. I'm going to guess that the reproduction cables offered all have the 5/16 head on both pos. and neg. cables, which is fine with me. As for the current batteries being sold, I'm sure Delco has a decent replacement for the Y77, at least I hope they do.
I was doing some online searches a few minutes ago and just found a post saying that the different size attaching bolts were an issue and were eventually changed. Knowing this will help cut done on the time it will take locating replacement parts, at least for me anyway. If you have the original equipment cables and the extra funds to purchase a known good NOS battery that would be good for some but I'm not that worried about it.
So someone is reproducing the side post battery topper now. I think ALL the stuff I've been reading is a bit dated for the most part. I'll have to look into what is out there.
1) I think your post is incorrect re the 'terminal polarities'.. See the pix of the Y77 from the CRG info site, attached below. you can see the polarity is POS on the left, and NEG on the right!
2) Per the CRG information on batteries, the R79 was a HD option to the Y77 (also POS on the left and NEG on the right) per the photos.
3) The original batteries (Y77) used different sized screw threads for Pos and Neg, but I believe all currently available batteries use 3/8" screws. Note: The screws inside the cables are removable/replaceable if you happen to have the wrong size and own a NOS Y77, OR the 3/8" screw can be cut down and re-die to 5/16" if needed.
4) Y77 batteries are no longer made or reproduced to my knowledge, but the R79 is available in reproduction ($340?). and you can buy a R79 battery 'topper' for $49 to capture 'the look'.
I believe the above is accurate as of 'today', and I'm sure someone will correct me if it isn't..