Yes, the one in the car (biscuit) does have the single tab idler arm mount. Any other advantages/disadvantages. What would you run? Would you all run a spool or a biscuit type if you had to pick?
When they mention single tab they mean stud mounted. The idler has a piece of metal on top where the bolt head is and on the bottom where the nut is.
On 67 K-members (and 62-66) the idlers has a tapered stud that comes out of it and there is a thick coin thats welded to a tab off the kember that the taper in the idler goes into.
It appears to me the first pics is not a 67 k-member.
67 A-body idler arm looks like this:
I don't have a picture of a 67 Idler setup, but here is a 62-66 stud idlers and it's very similar.