Grandma had the same problem with her Caprice.............Just kiding, If that was the ride I was fixing up I would go to the State auction and buy a wrecked Highway patrol caprice with a 350, most of those have some pretty good add ons to the motor and run real good, some even have the performace chips in them. Would be as cheap or cheaper than upgrading the 305. Seen them sell for 800 to 1200 or so.