I have a 68 RR that the vin decodes to a 68RR 383 4bbl 4 speed with a 3.55:1 sure grip. That is exactly what the car has in it. I looked on the engine block down by the oil pan to see if the numbers there matched the car vin but there were no numbers there at all. were they not there yet in 68? the engine pad on top has D383 and an HP on it. So it should be a RR engine. Is there a way to tell if this is the original engine? the guy I just bought it from has had it setting in his garage since 1993 when he bought it and it hasn't been licensed since 1985.