My dad has spells where he has vertigo lips tingle and has a weird chemically taste in his mouth, could this be signs of stroke?

Absolutely: And he should be seen. Also, rule out a focal epilepsy variant.

Possibly: Signs of stroke can vary greatly. What you described can potentially represent signs of transient ischemic attacks (or so called "mini strokes"). This requires careful evaluation by a physician. Other conditions can do this as well. Notably, seizures, anxiety attacks and migraines can present this way.