Suffix Code mystery
 

Hello all,

Have a very original low mileage '69 C-10 that was a fairly late build in that it was delivered on 8/7/69 with an engine assembly of 06/24. What I've not seen before is the suffix code, which "U5."

Anyone ever come across this before?

Thanks

Re: Suffix Code mystery
 

Post a pic of the pad.

Re: Suffix Code mystery
 

Here are a couple of the pad...undoubtedly a "5" and original stamping with discernible broach marks.

Re: Suffix Code mystery
 

Might be a miss stamp.
I’ve seen that before.
LMC shows ‘u’ suffixes for 69 on a 307.
What’s the casting number?

http://www.lmctruck.com/icatalog/cb/full.aspx?Page=10

Re: Suffix Code mystery
 

Also what transmission?

Re: Suffix Code mystery
 

I'm goin with UB: 69 307 2bbl manual trans (clearly a 5 as I'm lookin at it, but perhaps a mis-stamp, or the "B" was broken that day (i.e. I'm with Geezer!))

Re: Suffix Code mystery
 

Motor is a 307...block casting # 3970020. Manual transmission.

Kinda of thought "UB" would be correct for it also, but had been wondering if there was some secret casting I didn't know about :)

Probably right about the "B" being broken that day...either that or the engine stamper had broken glasses:)

Re: Suffix Code mystery
 

He was likely blind in one eye and couldn’t see out of the other!

BTW welcome to the jungle!

Re: Suffix Code mystery
 

geezer#99

Thanks for the welcome!

Re: Suffix Code mystery
 

You got pics of this truck?

Re: Suffix Code mystery
 

Here are a couple pics.

Re: Suffix Code mystery
 

Nice!
Clean too!
Thanx for the pics!

Re: Suffix Code mystery
 

Great looking truck! Thanks for posting pics.

Re: Suffix Code mystery
 

Very nice truck. I'm not all that far from you I live near the Rondout reservoir. But I am down in Wappingers falls regularly have a rental house there and a couple of my cars are in the detached garage.

Re: Suffix Code mystery
 

Such a nice looking truck! SPID pic in our future? ;)

Re: Suffix Code mystery
 

"U5" is the COPO motor...;) Nice score, welcome to the mayhem...

Re: Suffix Code mystery
 

WOW ! What a sweet looking truck.
Hope you plan on keeping her just the way she is.
Thanks for the pictures.

Re: Suffix Code mystery
 

Very very nice truck. I like it as a good example of "all the in between" you could get. There were the plain Jane utilitarian trucks to all the bells and whistles CSTs. Then there were those custom tailored for what would be important to an owner and what they had no need for. Some were customer ordered, others were a dealership's idea of what they perceived their market demanded, or to offer variation in sticker price to up sell those hesitant to go all out. Mid level trim and comfort, V8, chrome appearance items, and that's it. It also shows not all truck buyers were convinced an automatic, p/s, and p/b.

Re: Suffix Code mystery
 

Where did you find the copo suffix? I've got a 68 with the same u5# clear as day.

Re: Suffix Code mystery
 

I think he was joking. This makes it more interesting with two trucks having this code. Thanks for bringing it back.

How does GM replacement engine ID work? As in new vehicle warranty replacement.

Re: Suffix Code mystery
 

https://photos.app.goo.gl/x9zg1ZnxCedsmBNV8I know there was a couple of othe guys with the U5 CLEARLY stamped. It does seem like a mystery #, but im pretty sure it didn't happen that many times..lol I did see something about being a buick engine and with the blue/green paint, it makes me scratch my head! It is just an old c30, so a transplant is very possible.