I don't believe EMPI sold slip ins. They were all machine in (corrections welcome).
For the most part 88/90.5/92 cylinders all have the same OD.... I think the earlier ones (at least the 90.5's) have a slightly smaller OD at the case end.
I have 3 different size machine in 88 cylinders sets here,Empis are definately different from the rest,made that mistake before,then 90s have at least 2 different sizes for machine in as well,and i am fairly certain 90.5s have 2 sizes.My NOS alluminium 92s are in a container so cant check there size
Personally i wouldnt use the empi 88s for a regular street car,cost and age would make me use newer cima or mahle 88s when available
cheers Richie