Mine was in a 70 RR. I don't know how much help I'll be here. Mine was a 71 engine, high compression 340, completely stock except for (eventually) headers, and playing with various spread--bore carbs.
I am to this day amazed at how well that little engine hauled that thing around. It would stay with a typical stock 383RR, and would get over 17 mpg on the highway. That was a heavy car, for a RR, as it had the Dana axle, air grabber, and "hang on" A/C. I always had about 150--200 lbs of junk in the trunk.
