FWIW...The 70 Road Runner we still have was run with the STOCK OEM factory short block,heads were cut-.030 and were fitted with street hemi springs.Cam was(and still is) the old street hemi grind,750 Holley DP,TM-6,1 7/8th's Hooker headers,4-speed and 4.10 gears.Timing chain was double roller Zoom and we used a Zoom clutch assy.Tires- M&H stocker tires(I think they are the musclecar line up now) 10.5x28 on 8" wheel,Car ran 12.70's all day long.The fuel pump was a Holley mechanical with a red Holley electric out back with the stock 5/16ths line.Later we went with a 727,and a 4.88 Dana,larger headers and some other stuff(engine stayed the same) and eventually ran 12.25 in Atlanta on a 30 degree night.