I am going to look at a 91 Scottsdale tomorrow. the guy claims that before he bought it 12 years ago it had a newer motor put in it there is no proof of this however the VIN code says it had a 305 with a 5-speed manual from the factory the owner claims that the previous owner said it was a 350. I really don't care which engine has but I would like to be sure which one it has. What can I do to tell which is which is there an easy way?