First I would establish if the original 190 motor only jumped the one tooth. I think not but can be wrong. As for changing out the motor it is well within your capabilities. Just go at a sensible speed and pay attention. Your real problem becomes getting a really good used motor. Fortunatly you are in a prime part of the country for that pricewise as well as availability perhaps. I will not buy an engine out of a car used unless somehow or other tremendous faith in the seller is established. I want to hear it run and totally evaluate it first. It is a no brainer to have to change an engine twice when fairly easily avoidable. Too many people out there will say whatever it takes to sell something on far too many occasions. The actual engine change is the lesser and most managable component in my opinion. It should go pretty quickly and easily as well.