With a hot block and chilled liners they drop right in. I have a puller I use to make sure they stay seated as they cool. You can use a good mallet, and an insert to protect the upper edge of the liner, but it hasn't been an issue.
Both 2.5 and 2.8 are shrink fit. I have a used kitchen oven I picked up for free from someones kitchen remodel. My wife may have been fine with using hers, but I'm not going to push my luck.