No, they did make an RB 383 in 1960. A real oddball. I think I may still have the intake around here somewhere.....I thought it would be interesting to have a 440 with a factory looking 2bbl on it. On your engine choices....decide what you want to do with the car (race, strip/street, cruise, grocery getter, etc.) and then build the car accordingly. A small block setup is the cheaper, easier to work on choice. Forget the poly 318. An LA360 would be my first choice if money matters, a crate 408 if it doesn't. An LA318 is fine too if you're willing to give up some horsepower to keep reliability.