is the GVW the best way to tell a big block?

[vettedad61]

I have a 1972 Super Cheyenne big block, I was told it's a factory big block truck, it's a non-original engine (1973 454) the build sheet is long gone and the spid is missing, its been repainted a different color, the VIn in the cab is original and matches the frame, factory short bed, low hump, no heat sheild but has dual exhaust hanger.
I am trying to determine if this is a factory big block truck based on the gross vehicle weight on the VIN plate?

http://67-72chevytrucks.com/vboard/s...ight=vin+plate

[Longhorn Man]

I don't know of GVW showing anything like that. The best signs of a factory big block would be exhaust hangers on both sides (no factory dual exhaust on small blocks), a heat shield on the lower passenger side firewall, and a high hump cab floor on all but 3 speed manual tranny trucks.

[71 super]

Check some posts by dantip, the gvw is the about the only way you can tell without the spid in a 1/2 ton 2wd. As I am sure you know the vin indicates only that it is a 8 or 6 after that without spid and the tell-tale parts- i.e. heat shield, dual hangers (three locations on both sides) correct parts such as remote reservoir, clamp to hold pressure hose at motor mount, correct mounts, auto cross member with guides for brake intermediate cable at trans mount, two piece drive shaft, 3.07 gear if auto. Thee are just off top of my head there are others. Might contact Paul Duncan as well he can help.