Yes, 68 and 69 switched to hydraulic cam like the new 318 that was released in 68. The 318 LA replace the 318A which was the Poly 318. The old Poly had solid lifters as well.
The LA318 was introduced in 1967. There were some poly engines that had hydraulic lifters. I used to have a couple. I'm trying to remember what they came out of.... industrial or marine application probably.