10 20 30 1/2 3/4 1 Ton

[69C-owner]

Ok I wanna figure this out finally, ive always figured 10 is half ton, 20 is 3/4 and 30 is 1 ton but I've seen some odd things like a 20 with duals....so?

[hugger6933]

Gmc did the 1500 2500 3500 thing that should help in the confusion. That might lend to the theory that GMC trucks are tougher[ can you hear the worms coming out of the can I just opened?] Auctally , most of that about GMC being better goes back to a time when they had air filter systems that worked better and that made the engines last longer. any way, back to your question I don't think the dual wheels were ever a 3/4 ton option i've never seen one. Most likely you saw one that someone put heavier stuff under.

[SS Tim]

The 10,20 and 30 number all represent GVW weight ranges. For GM of this time period I'm showing:
1-3900-5800 lbs
2-5200-7500 lbs
3-6600-14,000 lbs

And yes, it was possible to order dual wheels (RPO RO5) on a C20.

[Longhorn Man]

Drw could in fact be ordered on a c/20 if it was a cab/chassis only.
You are right on the half ton being a 10, a 3/4 ton being a 20 and one tons are 30 series.
Posted via Mobile Device

[Longhorn Man]

I shoulda hit refresh first huh?
Posted via Mobile Device

[slomotion]

Well, seems there's exceptions to everything. Here's a couple pics of the original paper work that came with my truck. There were 1103 flatbed C20's ordered in 1968 (according to the resto-pack people), and the dual rear wheel conversion was available at the factory. Chevrolet didn't keep track of anything that was less than 1% of a production run so it didn't happen very often, but there's 11 or less of the factory C20 dually's running around. I know of two.......

[bollybib]

You guys know a lot more about these big trucks than me by far .,,.but what the heck does "dual rear chassis provisions" really mean ???

[feller]

longer wheel studs to acomidate 2 rims in the rear, mabey??