I have a 67 Cutlass Supreme convertible I recently obtained and much to learn about! First off, I thought this was a 330 ci but don't know which hp. However the engine casting number 394417 is a 330 cid, and the stamp pad number V55147G is a 400 cid high compression. Confused!~! It has a 4-barrel rochester carb and single exhaust. I'm sure it is a 330 with a factory stamp pad error? Which horsepower rating would it be? Also there is no dipstick or dipstick tube in the motor! Where about should that insert the block? Thanks for any insight regarding my delimma!