Hello, I have the factory booklet for 1971 covering all the models. They say the redesigned engines can run on unleaded regular or leaded regular or any grade of gas. First year for the redsigned G-Machine ride for handling. They moved the steering box to the front and front disc-brakes standard on the 88/98's. I have two 1971's, a convertible Delta Royale & a 98, both 455's, both lo-compression. Lo-comp. is really not a bad thing, one can run any grade of gas. My Delta will roll pretty good. Even though it is still 8.5 to 1 compression, I figure it is 350 HP at the flywheel. It's rebuilt, Comp's Cam 268H, .456/.456 lift, Edelbrock Performer intake, Holley 670 CFM, Crane modual, Hooker Headers, Torque-tube, 2 1/4" dual exhaust. I really like your 71 Delta. The early Deltas had "more" louvers in the trunk-lid. After the first month they changed it to less louvers, both mine have the less louvers as yours does. They problem with the more (double) louvers were exhaust fumes were being pulled up into the vehicle so fumes could be smelled. New design, ess louvers, foam rubber eliminated the fumes. Nice car!, Ken
