coil pack question

[scoobyfuzzy]

just a quick question about coil packs. me n ma mate both have a my93 wrx import scoobs, but knoticed tday his coil packs are different than mine, mine r the ones that are bolted on to the head with 1 bolt, and the ones on ma mates are bolted on with a bolt at both sides of the coil packs. iv never seen these coil packs before, so my question is, was ther a change in coil packs at some point, or is ther 2 different types of coil packs, for different engines etc?  just a bit curious about this

thanks in advance

 

fuzzy