Just how much of a moron am I?

[Ovals_and_Bowties]

Now I wanna go pull the numbers on the tranny. I'm just not sure where to find them right off.

 

[ali_c20]

Well I finally decided after having my square for over a year. Whilst knowing there was a rebuilder's plate on the block to, ya know, actually check the damn numbers on the block... And, uh, well, it explained a few things. Namely why my gas mileage wasn't what I thought it should be and why the engine wanted the carb jetted so rich. My 305 was, in fact, a 350 in disguise the whole time. Specifically out of an 83 C10, which also explains why my 85 has a TH350C in it. Someone gutted an 83 to keep the 85 alive sometime back in the 90s.

Lucky guy, I had a smog 305 instead of the original 350 in my C20. Was too lazy to scrape of the inch of grime to check the numbers. Stupid me.

 

[Ovals_and_Bowties]

Lucky guy, I had a smog 305 instead of the original 350 in my C20. Was too lazy to scrape of the inch of grime to check the numbers. Stupid me.

305 in a C20? Oof that's rough. Is she auto or stick? If she's auto, get an add-on cooler, then you can reef away on the torque converter to get her moving when towing and/or going up hill.

 

[ali_c20]

305 in a C20? Oof that's rough. Is she auto or stick? If she's auto, get an add-on cooler, then you can reef away on the torque converter to get her moving when towing and/or going up hill.

I do a full rebuild at the moment and now a 350 with Brodix heads and and a low end torque cam is in. Rebuilding a 700r4 for it.
It has 4.10 gears and I didn't tow with it or put on heavy loads so it was not bad to drive.
It won't do hard work in the future, more a recreational truck.

 

[TotalyHucked]

Rockauto, Autozone, and O'Reillys all swear 1983 was the last year for the TH350 with only TH400 or 700R4 being listed for an 85. Seems like GM kept it around a bit longer and forgot to tell anyone.

Meh, parts stores rarely have their listings 100% accurate anyway. Especially on old stuff

 

[DoubleDingo]

Meh, parts stores rarely have their listings 100% accurate anyway. Especially on old stuff

Yep. If I listened to the snot-nosed kid staring at the screen, I be buying the wrong parts for my 81 every time. They always tell me it's a TH350 because it has a 350 in it. When I tell them it's a TH400, they tell me it is a 454 engine.

 

[TotalyHucked]

Yep. If I listened to the snot-nosed kid staring at the screen, I be buying the wrong parts for my 81 every time. They always tell me it's a TH350 because it has a 350 in it. When I tell them it's a TH400, they tell me it is a 454 engine.

Or like the guy that refused to sell me the parts I needed one day. I'd already gotten him to pull me the parts I needed for the '85 truck itself (some brake stuff I think). Then I was moving on to the list of things I needed for the '06 engine and made the mistake of mentioning I'd put that LS engine in the '85. He refused to get me any of the other parts, saying he can't sell me mis-matched parts and that it's not possible to do what I said I did. Said I was making it up. Needless to say, I left the other parts on the counter and walked out.

His face was priceless a few months later when I stopped by with the completed swap and specifically called both he and the manager out there to show them. He got his ass chewed

 

[Bextreme04]

Now I wanna go pull the numbers on the tranny. I'm just not sure where to find them right off.

My TH400 has the partial vin stamped on the transmission right above the pan rail on the passenger side. It is that way on my 1980 K25 and on the 67 Buick Riviera TH400's. They stopped doing that at some point, but it was still being done in 1980 at least.

 

[Keith Seymore]

They don't call it a 350C, but it does list the 3sp automatic option for both the 305 and heavy duty trucks. If you have MX1 on your RPO sheet and it was originally a 305, you would have gotten the TH350C. MX0 would mean it originally had the 700R4.

You must be registered for see images attach

You must be registered for see images attach

I think 85 was the last year for that. After 85, it was either TH400, 700R4, or manual only.

I have to admit I panicked a bit when I saw my name associated to a thread with "moron" in the title.

Anyway - the RPOs shown here (MXO, MX1, MM3, MM4) are the "Merchandised RPOs"; the ones the customer and dealer get to pick.

M20, MY6, M40, etc are all "non-Merchandised RPOs". The engineering charts pick those.

https://www.gmsquarebody.com/threads/rpo-not-idd.49120/#post-1058009

K

 

[Ricko1966]

Where ever you were looking up parts messed up.

 

[Ovals_and_Bowties]

Where ever you were looking up parts messed up.

I almost asked where the hell you were rebuild kit shopping that a TH350C banner kit cost near $200, then I got a better look and realized it was a master kit.Oops.

I got a banner kit for $100, now I just need a half-decent core to build then I'll have me a spare.

 

[Ovals_and_Bowties]

I have to admit I panicked a bit when I saw my name associate to a thread with "moron" in the title.

Anyway - the RPOs shown here (MXO, MX1, MM3, MM4) are the "Merchandised RPOs"; the ones the customer and dealer get to pick.

M20, MY6, M40, etc are all "non-Merchandised RPOs". The engineering charts pick those.

https://www.gmsquarebody.com/threads/rpo-not-idd.49120/#post-1058009

K

Don't worry I'm the moron in question.
I had seen the sheet in my glove box just said 3 speed auto next to it with no further elaboration as to which one.

Good thing I crawled under the truck to double check what was actually in the truck.

 

[Ovals_and_Bowties]

This is what comes up when I search last year for the TH350C in C10 trucks. I could swear I read somewhere else that said 83' was the last year. I wonder where the hell that (apparent) piece of misinformation got started?

You must be registered for see images attach

 

[HotWheelsBurban]

I know our 84 C10 Burb had a 700-R4, I don't recall what the 81 Sierra shop truck had behind its 305. Might have been a 350C....

 

[TotalyHucked]

350C was the standard trans, 700R4 was the optional one until '87