big 10's anyone?

[Keith Seymore]

Wow. You guys have been busy...

I don't have anything to add, other than to say California did have more stringent emissions regulations that "Federal" emissions regs back then (that's why there were differing engine RPOs. Incidently, these days more and more states are signing up for California style requirements). I can't comment on Canadian regs, but back then I thought they followed US Federal regulations.

My baseline is that '75 was the first year for Cats on a 1/2 ton Federal truck. California may have been different than that, and "bigger" trucks would follow after that.

As was mentioned earlier, the "Big 10" was an option that was added to the existing truck (ie, Scottsdale or Silverado), just like the trailering option could be added without changing the trim level.

K

[bluex]

Thanks Keith

I know you said you started on the line in '79, so I thought you might have some solid info about which trucks got cats and which didnt.

Dosent matter to me at all here in SC, no inspections or smog checks!!

[turbo350]

My Big 10 is a '78 and came from the factory without cats. Another way to determine if it ever did come with cats is the size of the opening for a fuel nozzle at the filler neck. If the truck didn't have cats from the factory the fuel opening would be the bigger of the two so it could accomodate the larger diameter nozzle that leaded fuel pumps used back in those days. Another indicator is the fuel guage. My truck it just says "fuel" underneath the guage, where as trucks with cats I think say "unleaded fuel only".

At the time I had really no idea what a Big 10 was. I bought the truck because it was a solid machine not really because it said Big 10 on it. I learned quickly that these were indicators that this truck never had cats from the factory because back in the mid 90s we had emissions testing here in MN in order to renew our license tabs. I had the techs scratching their heads and they weren't going to pass me at first. My truck was completely stock at that time. The internet was not around at that time (at least not in my world) so I didn't have the luxury of pulling up a website to back up what I was saying. They eventually let me through. Funny thing is the guy said I almost passed the sniff test anyway.

[TravisMartin]

Here's the deal...Keith is right; cats started in 75. But at that time, they were only required on pass cars and light trucks; the law (fed, not Ca) read "trucks over 1/2 ton" were exempt.

So GM sez "AHA! a loophole!" and started marketing the Big 10 (GMC called it a "Heavy Half") The salesmen even referred to it as a "5/8 ton"...since the law exempted "over 1/2 ton" from cats, that got 'em around it. (Sorry if you were in Ca...they didn't get exempted...)

But then the feds caught on and changed the law to say that under 3/4 ton had to have cats just in time for the '80 models to come out. So beginning in 80 all half tons had to have cats. But the Big 10 was already in the lineup and selling well so they kept going with it. I bought mine Jan 22 1980...yep, it had cats...they dropped the decal the next year since it didn't mean anything anymore.

Catalogs like LMC still sell the "Big 10" and "Heavy Half" decals...

Anybody know when they started requiring cats on 3/4 tons and 1 tons? My '90 R3500 is a single 3" exhaust with a big cat; when did that start?

Travis

[big10ratrod77]

Catalogs like LMC still sell the "Big 10" and "Heavy Half" decals...

man you got the part number for the decals ive looked and i cant find them

[Restrorob]

Originally Posted by TravisMartin

Catalogs like LMC still sell the "Big 10" and "Heavy Half" decals...

Originally Posted by big10ratrod77

man you got the part number for the decals ive looked and i cant find them

Better yet Travis, A link to one of these catalogs showing these decals ?


I looked ALL over the net and found nothing, Ended up getting a graphics guy to make my "Heavy Half" decals;




Thanks

[3r!c84]

try ebay i looe and found a few BIG10 ones

[kris's66lwb]

thanks guys that helped alot my truck is anb all origonal 1980 chevy bonanza big 10 it has a 350 350 combo with a dana 44 i think it is with 411s i have outlaw iis on it with 30s in the front and 31 31.5s i out back adding to that *****en raked look

[RoughKuntry]

1980 Chevy Big 10, with 4.3 292 I-6 Pulled from another 1986 Big 10. Power: 115 hp (86 kW) @ 3400 RPM, Torque: 215 lb·ft (291 N·m) @ 1600 RPM. 33x14.50R15 Mickey Thompson's Baja in the rear, with Wild Country 30's up front. All I know is this one still has a converter, But as soon as I rip the darn thing off and add my 1973 Original 350 5.7 V8 I can stick back to my Glass Pack Exhaust. Even after I removed the rear tires and put her back to stock her Bed was still lifted. Reminds me of a Race Truck. Only thing different, is 2nd Gear is about to go out. Luckily I have another 4 Speed ready. This isnt all the problems.. My truck has abit of rust in the door jambs & Needs Major Detailing to the Passenger side of the body. Previous owner put her into the guard rail near Everette, Wa.

[RIDE-RED 350r]

This seems like the best thread about the Big 10/Heavy Half I could search up...

My question is this:

Are the 4x4 short bed Big 10/Heavy Halves much less common than their 2wd and long bed counterparts?

I ask because that is what I have and looking around here it seems that the vast majority of these trucks are long bed and many 2wd.

[RoughKuntry]

Somewhere in my stuff I still have the Big10/ Heavy Half steel logos to bolt on the back of the bed or tail gate.