Noises from 95 s 10

I just changed my spark plugs on my 95 s 10 4.3 v-6. now i have a ticking noise and sorta of a sputtering, it sounds more like a old steam train going down the tracks when idiling. what could be causing this. oil level is fine. And another note when i got the oil changed they told me i have a big oil leak and they don't know where but my dip stick is full

I just changed my spark plugs on my 95 s 10 4.3 v-6. now i have a ticking noise and sorta of a sputtering, it sounds more like a old steam train going down the tracks when idiling. what could be causing this. oil level is fine. And another note when i got the oil changed they told me i have a big oil leak and they don't know where but my dip stick is full
Ticking like spark jump?
Check wires and cap and plugs.

On the oil leak ask them where it is leaking or crawl under there and have a look round.

could be the #3 plug. mine will tick if its not tight.