I ordered My 1969 SS427 Impala before the order sheets were available at My dealership that I worked at. The owner filled out a 1968 order sheet. My order included the L72 425 H.P. engine. It was a special order even in 1968. G.M. made it available. Now to today. The Comp .652 solid cam with roller rockers and headers make about 500 H.P. with dual pump, 780 carb. With 245 tires in front and 275 60 tires on rear and 373 gears, with rear sway bar : It is more than I expected. It is fast and handles good. I live on winding roads. Trying to get a video on here. NICK L72