Is this right?
 

Re: Is this right?
 

Basically, yes. My 75 C10 is classified as a heavy duty and never had any emission stuff other then PVC and Thermac. Gas gauge specifies fuel, not unleaded fuel. And it has the larger leaded fuel inlets. Gross weight is listed as 6200lbs but the empty weight is 4100lbs IIRC.

The Heavy Duty option was fairly common and didn't require the Heavy Half or Big 10 designation.

Re: Is this right?
 

They didn't weigh over 6,000 lbs. They had a GVWR of greater than 6,000 lbs.

Re: Is this right?
 

That's interesting. I have an '85 HD 3/4 GMC that came with no catalytic converter from the factory. I was told that it was exempt because it was considered a commercial vehicle.

Re: Is this right?
 

My 83 C20 has no cat or evap canister but has lots of hoses, pipes, and valves for smog compliance (and it gets checked for all of that stuff when it goes through emissions every year.) GVWR is 8600#, empty weight is about 5600#.

Re: Is this right?
 

My 78 is a Heavy Half C 10 and was exempt for Cats, but still had to have it "sniffed" every year, just barely made it every year,
So 2 years ago I upgraded it to a LS 4L60E conversion so it would be cleaner and get better gas mileage,
I then took it to the inspection station for a sniff and they rejected it because it did not have cats, of course it came from factory with out cats but now that I made it "cleaner" I am required to have cats.

We need more govmnt' in our lives !!