The V in the serial number indicates this car came with a V8.Unless you have the factory build sheet their is no way of knowing what V8 was installed. These were the engine options Their was a 265 cu. in. V8 ' ' ' 283 ' ' ' 2 BBL ' ' ' ' ' ' ' 4 BBL ' ' ' ' ' ' 2x 4BBL ' ' ' ' ' ' with fuel injection Your car is original the day it leaves the factory.If the original motor has been removed and a different motor installed even if it is the correct year your car is not original.A period correct motor is good but the original motor adds a lot more value.In other words numbers matching.

Typically casting dates anywhere from 2 to 6 weeks prior to the car's build date are acceptable. This can vary slightly between manufactures. In your case, an answer might be "It depends". If your car's build date is early June and the engine casting date is late April, there shouldn't be an issue. However, if your car's build date is late June it most likely wouldn't have an early April engine. Remember, if you are concerned with engine casting dates, all the engine component dates should be within a few days of each other. Hope this helps.