There are many tell tale signs if a truck really is a 454SS. Sure the VIN is the proper way, but I can tell a fake usually without looking at the VIN.
5 lug 9.5" 14 bolt
TH400 (1990) or 4L80e (1991-1993)
Seats (1990 & 1991 454SS specific seats), but all 454SS trucks had buckets/console
Dual exhaust (1991-1993)
110 mph speedo (tach on 1991-1993)
rear cab light
rear slider
Mirrors (recently I heard Canadian trucks had the dumbo mirrors, but every 'real' 454SS I have ever seen has the small sport mirrors)
Wheels/centers (black with red bowties or chrome with red bowties)
Side trim/emblem (no red stripes as on a Sport truck, but red/black C1500 emblem)
Black Grille/red bowtie
Silverado trim with Console, Cassette player, tilt, cruise, PW, PL, A/C
of course the 454 - Mark IV (fuel pump boss/2pc rear main seal/black steel valvecovers) in 1990 & Mark V (no fuel pump boss/1pc rear main/aluminum valve covers) in 1991-1993
As I type this, I realize many may think my 454SS isn't really an SS, as most of this is long gone. It definitely started life as a 454SS.
Most 454SS clones I have seen (I have seen many) do not get everything correct. I've seen bench seat, standard dumbo mirrors, no rear slider, 700R4/4L60e, 85 mph speedo trucks with a 454 in them and claimed to be an SS. I've seen Sport model trucks with a V6 and 454SS badges. I've also seen Suburbans, duallys, etc with 454SS stickers on them too.
