Hybrid117

Is my tranny a th350 or a th350c? How can i tell? and do they make stall converters for it?
1980 L82

a1sensei

Th350

Sixminuteabs

My 1980 is th350c...I have a stock and functioning lock-up converter.

Not sure why the above guy automatically told you that you have Th350???

DEMITRISTYLES

All 1980's with an automatic transmission had the TH350C.

peace and love

tomard

Would have been real easy to look ..... if it has electrical connector rear of manual shift linkage, then it is a lockup (350c)

rclinton

Not all of the 1980's have the TH350C I believe the early build like mine had the TH350 and the later builds had the TH350C. JUst check for the electrical connection like the early poster stated. Bottom lline is that yes they make stall converters for both.

Ditmeion

My '80 was built in Oct '79 & I do indeed have the th350c.
Just look for the vacuum switch by the distributor or look for the electrical connector on the tranny...drivers side I believe.
TCI makes a stall for it, I think.

1980 blue L48

You can also look for your last 4 digits of vin, at drivers side tail extention. I believe just forward of the speedo cable? cant remember.

str8upchevy

Unless somebody changed it, you should have a TH350 in there. (If there's any question, read the next post)

If it "IS" in fact a TH350C.....you have two (2) options for running a stall converter. As stated already, TCI does make a stall converter for it. It's only a 2000 RPM converter (which IMHO is a waste of $385) .....especially if you're not running a lot of HP & TQ. Odds are you won't even really feel it.

Option two is to buy the Hughes 2500 RPM converter. You get more converter for less money,..($334).....and with a 2500 you'll be able to notice the difference.

Here's a link to both converters..... http://store.summitracing.com/egnsea...=KeywordSearch

Hope that helps!

str8upchevy

Click the links below and read about the 1980 Specs,....then click and read the 1981 Specs.

The 1981 model was the first year for CCC (Computer Command Control....which I think controls the lockup converter) My 1980 that I had last year didn't have a TH350c transmission in it. But then again it could have been changed out.

Click the links below and read what it says about the 1980 Corvette. Then click on the other link and read what that page says about the new 1981 model's "new lockup converter".

1980 Model .........Make sure you also click on "1980 Corvette Specifications" above the article.
http://auto.howstuffworks.com/1980-corvette.htm
1981 Model .........Make sure you also click on "1981 Corvette Specifications" above the article.
http://auto.howstuffworks.com/1981-corvette.htm

1980 blue L48

WRONG !!!! My 1980 is all stock , built 12-7-1979, VIN is stamped on trans & Block. It has TH350c with Locking converter. Its actuated by a switch between the master cyl. and Dist., works off vacume minimum of 3 inches.

str8upchevy

If the lockup isn't controlled by the CCC, then I stand corrected. I was going by the information I read on that website.

Binnie77

The TH350C was introduced in 1980 as Code MV4 and 34,838 cars were produced in 1980 with that transmission. The TH350 Code M33 was also available in 1980 BUT was installed in the California optioned cars only. The TH350C code was changed to MX3 in 1981. The earlier MV4 coded cars used a vacuum lockup switch which was also integrated with the brake light switch.

Reference: NCRS and GM Parts Catalog

stingr69

My 1980 L-82 was built during the last 2 weeks of production. It does not have a lock-up converter. The car is very stock with 57K on the clock.

-Mark.

str8upchevy

Thanks for clearing that up Binnie, ...it looks like their website has a few minor adjustments that need to be made.

stingr69

The NCRS manual appendix I have lists (3) automatic trannys for 1980 (page 126):

MV4 = THM 350C
MX1 = Automatic Transmission
M33 = THM 350 (for California)

I must have the MX1.

-Mark.

2airtime2

I'm not sure which th350 my '80 California car had but it does have a green wire in the wiring harness that the previous owner labeled "lockup".


I've pulled that trans (shifted fine) and installed a 700r4 with od and lockup.


The th350 is for sale. $2000 and you pick up, service my rear wheel bearings, and clean garage floor when done.

Street Rat

If you are going to pull the converter and change it. I would put in an automatic overdrive instead messing with the TH350C. Either a 700 4R or a 200 4R. The 200 4R is a direct bolt in for the 350C.

7T1vette

Doesn't make sense to remove the 350 trans, replace converter, and reinstall when you can get a 'fresh' 700R4 with whatever converter you want for a little more money. If you drive on highway at all, the O/D trans is WELL worth the difference in money.