Darkamber8828 currently the Z-conversion set of choice is:
Porygon @ Normalium Z
Ability: Download
Level: 5
EVs: 36 Def / 236 SpA / 196 Spe
Timid Nature
IVs: 0 Atk
- Thunderbolt
- Recover
- Ice Beam
- Conversion
This makes Porygon Electric typed, and gives it more or less perfect coverage. Recover gives it hella bulk and lets it beat the two things which BoltBeam coverage fails to dent / OHKO hard. As an Electric-type, you're able to set up on the likes of T-wave mons (i.e. Defensive Pory, Ferroseed, Slowpoke) which is solid as hell. More importantly, you are no longer weak to any priority attack. Plus STAB T-Bolt is stronger than STAB Tri Attack is in terms of raw power, at +2 that's a bit noticeable. I haven't tried HP Ground in the last slot, but that seems perfectly acceptable to have, especially on something like Spike Stack or whatever. That being said there isn't much of a reason to use HP Ground in general, hence why I have yet to.
This in tandem with Shellder and a Dark-type has been rather effective at steamrolling the ladder. Porygon is a great 'oh shit i'm bored of this game' button tbh, to the detriment of the tier.