The 671 fit, but not without problems. No engine fan, used electric pusher fan on the bumper side of the radiator. Firewall was "extended" into the cab area to get the long 6 cylinder in. The guy got the 671 cheap, so did not mind the extra work to install it. A 471 should not have the fan/firewall issues. 2 inches is not much, but the clearance from steering/suspension to the hood are tight. A louvered hood could solve the issue.
83 C10 Suburban, Silverado, 6.2, 700R4, 3.73, 31-10.50R15
82 C30 Crew Cab dually, 6.2, Banks, Th400, 4.10, Gear Vendors, 235-85R16
83 C20 Suburban, Sierra Classic, 6.2, 700R4, 4.10, custom paint, 285-50R20
95 Yukon, 6.5, 4L80E, 3.42, 265-50R20
73 GMC Astro 95, 8V71, 10 speed Roadranger, 110" WB, 6 each 11R24.5