i thought 69 1/2 was first year for a 440 in a rr. if you are building a pretty much stock street car motor, meaning adding headers and a intake either the 383 or the 440 will work just fine. you will not be using all the power that either of these motors will produce. you are driving it and once in awhile burning the tires. if you think that you need a little more power build either one. i like the 383, doing it over i would have used our 426 street wedge.