Picked up a 73 C20, low original milea

[Corts60]

Well hello all!

I haven’t been on here much lately because I really haven’t been tinkering with my trucks lately….But! This weekend I picked up a 73 C20 with only 31k original miles! She lived on a farm in the middle of Illinois her whole life. I hopped in and drove it 240 miles home without a single issue. It has a 350/SM465. Not sure gears yet. I think 3:73.

Here are some pics after a quick wash and before I really started cleaning!

[Corts60]

And here are some after I pulled everything out of interior and cleaned up 50 years of dirt. I brushed up loose rust and put corroseal on to stop it from spreading. I also scrubbed all the upholstery and the floor mat.

[Corts60]

Then I thought I would do a little buffing and get the front bumper looking a little better.

The plans are just to drive it and leave as original as possible. It isn’t perfect, so I can still use it as a truck and not feel bad about it.

[Greg58]

Looks great! Enjoy!!

Greg

[MusicMan70]

Nice find and the bumper turned out great! I like that green as well, Congratulations on saving another one Cort!

[Keith Seymore]

Noice!

If you find the SPID label I can probably tell you what rear axle ratio it has.

K

3.73 is standard; 4.10 and 4.56 optional:

https://www.gm.com/content/dam/compa...olet-Truck.pdf

[Shifty One]

outstanding!

[Corts60]

Originally Posted by Keith Seymore

Noice!

If you find the SPID label I can probably tell you what rear axle ratio it has.

K

3.73 is standard; 4.10 and 4.56 optional:

https://www.gm.com/content/dam/compa...olet-Truck.pdf

Here you go! It doesn’t list the RPO for the axle. As you can see, she is a bare bones unit. The only options they chose was gauges and power brakes. It is a radio delete, lighter delete, everything delete truck. Haha.

[Corts60]

Here are some pics of the engine compartment. Only things changed so far is radiator and HEI. I need to get some valve cover gaskets on her before I drive too much more.

[Keith Seymore]

Originally Posted by Corts60

Here you go! It doesn’t list the RPO for the axle. As you can see, she is a bare bones unit. The only options they chose was gauges and power brakes. It is a radio delete, lighter delete, everything delete truck. Haha.

Yep - if it's not on the SPID then it came with the base axle = 3.73.

No tellin' what's in there now.

K

[Corts60]

Originally Posted by Keith Seymore

Yep - if it's not on the SPID then it came with the base axle = 3.73.

No tellin' what's in there now.

K

Thanks Keith! So far as I’ve found, she’s basically 100% original. Still has the shocks on it that has the spirals in the metal. So I’m thinking still has the 3:73 as well.

[65chevysub]

Beautiful truck. Consider joining my FB group: All Original Squarebodies.

[lolife99]

Wow. Such a killer truck.

[TKCR]

Wow! Thats nice. I would have sworn that was a Pearl Gray interior, but the spid says Slate Green.

[jerry moss]

nice score, congrats.

[Dead Parrot]

That MFG date of May 97 on the valve cover is interesting. Whatever the story is on the motor, nice looking truck.

[Corts60]

Originally Posted by Dead Parrot

That MFG date of May 97 on the valve cover is interesting. Whatever the story is on the motor, nice looking truck.

It actually says May 1973, you just can’t really tell in the picture. And thanks!

[ACS]

That’s a great truck. Every now and again a nice farm 3/4 ton turns up. You got lucky.

What rear axle does it have? Semi or full float? If you’ve got a full float 3.73 that’s pretty nice with the 465.

I’ve got the same engine/trans combo is you (just coming up on 50,000 miles this summer) but with a 4.10 in the back. It turns a lot of rpm on the highway.

[Corts60]

Originally Posted by ACS

That’s a great truck. Every now and again a nice farm 3/4 ton turns up. You got lucky.

What rear axle does it have? Semi or full float? If you’ve got a full float 3.73 that’s pretty nice with the 465.

I’ve got the same engine/trans combo is you (just coming up on 50,000 miles this summer) but with a 4.10 in the back. It turns a lot of rpm on the highway.

Thanks! The rear is full floating. I just don’t know what gears yet. I drove it home at 60-65 mph and felt that was as far as I was comfortable winding her up without a tach.

[ACS]

Originally Posted by Corts60

Thanks! The rear is full floating. I just don’t know what gears yet. I drove it home at 60-65 mph and felt that was as far as I was comfortable winding her up without a tach.

Mine had the build sheet under the passenger side of the seat - tucked in the springs. My rear axle code is GT5, which is a full float 4.10

[Dead Parrot]

Originally Posted by Corts60

It actually says May 1973, you just can’t really tell in the picture. And thanks!

That makes more sense. It really looks original. I bought a replacement motor for my 75 around 97 and it was one of the black Hecho in Mexico 350s.

If that is the OEM exhaust system, make sure it isn't one of the double wall exhaust pipe setups on the y-pipe. If the inner wall collapses, all sorts of bad things happen.

[Corts60]

Originally Posted by Dead Parrot

That makes more sense. It really looks original. I bought a replacement motor for my 75 around 97 and it was one of the black Hecho in Mexico 350s.

If that is the OEM exhaust system, make sure it isn't one of the double wall exhaust pipe setups on the y-pipe. If the inner wall collapses, all sorts of bad things happen.

Good to know! I’ll watch out for that. They pipe I’m pretty sure is original.

[Willowrun]

Always liked that color and ‘73’s are just cool. Nice truck!

[ACS]

Originally Posted by Dead Parrot

That makes more sense. It really looks original. I bought a replacement motor for my 75 around 97 and it was one of the black Hecho in Mexico 350s.

If that is the OEM exhaust system, make sure it isn't one of the double wall exhaust pipe setups on the y-pipe. If the inner wall collapses, all sorts of bad things happen.

Mine still has the original Y pipe. What’s going to happen to it?

[Dead Parrot]

Originally Posted by ACS

Mine still has the original Y pipe. What’s going to happen to it?

IF it has a double wall pipe, the inner wall can collapse and block off the exhaust flow. Symptoms are crappy performance and carbs that keep going bad. My dad bought what is now my 75 in 78. Its performance sucked. It had problems going faster then about 60(during the 55 speed limit era). Plus the carb kept going bad and flooding out. The thing looked like a diesel going down the road. When the thermostat stuck shut, the head gasket cracked. Turned out to be a good thing. While the heads were off, I looked down the exhaust pipes and noticed that both were blocked off even though the outside looked normal. Took it to an exhaust shop and they said they had seen several of the newer GM trucks with that problem. Swapped to a dual exhaust and suddenly it ran much better. 90+ with more left(younger and stupider).

Don't know if the double wall Y-pipe was a converter thing to keep the exhaust hotter or a noise thing. Mine never had cats being a HD version but I can see GM using the same Y-pipe on both versions.