My transmission is a 2 speed auto (I've never had the car on the road, so can't even be 100% on that), but I don't know whether it is original... On this site, and in my manual it says I should see a MA code somewhere (my engine is a 326 2bbl no AC), but I can't.

Here's a picture:


I see the numbers:
67
LC190D
1372028 (and then a logo, and then a small 4)

Can anyone help with identifying this transmission?

On the Turbo 400 there is a small (about 1.5 inch x 2 inch) ID plate riveted to the side of the tranny. The 2 letter tranny code is on there.

On Fred's Pontiac info site, he points out that the code for Turbo 350's are in a location similar to what you are showing. I am going to see if I can find your code.

Thanks for your assistance.

There are definitely no other codes anywhere on the casing.

Here are some pictures that may help:

OK, those pictures helped. I was able to look at the sketches in the 1968 Firebird Service Manual for a 2-speed tranny and your's matches.

So you do have a '67 BOP Super Turbine 300. I just have not been able to find the "LC" code yet. From the code patterns I see, I am leaning toward anything with "L" as the first letter being for a 6 cylinder engine. Tempest's have "LA", "LB" and "LD" listed but no "LC"

Found it.

LC is an ST 300 in a 68/69 Buick with a 250 cid 6 cylinder engine.

Buick Tranny Codes

I managed to find one mention an LC code...

From here: http://www.442.com/oldsfaq/oftrn.htm

ID ___ Year ____ Application
LC ___ '74 _____ 4V 350 Cutlass
LC ___ '75 _____ 350 Cutlas; 350 Wagons (Calif)

But that's with reference to the TH-350.


If the transmission is "designed" for a 6 cylinder, what are the ramifications of it being used with my 8?

Also, do you know what the other numbers tell? Presumably 67 is the year, and 1372028 a serial number, but the 190D?

Ah... posted my reply before I saw yours...

My educated guess from the Camaro info site is that "190D" is the date code the tranny was built. Still looking.

If you are going to "hot rod" your V8 much at all, I think you need to go with a TH 350 or 400 tranny.

Thank you very much for all your help, salmon38.

I was planning in the future to drop a different trans in, probably a TH200-4R, but that's looking a little expensive for right now, so I'm thinking a TH350 will be fine and just keep that in.

Is the TH350 a direct replacement for the ST300 in terms of driveshaft and crossmember?

Now it's got me worried as to what exactly the rear-end is...

I forgot - but did you get the background info for your car from Pontiac Historical Society (PHS)?

I'm going to check on the direct swapping of an ST 300 for a TH 350 here in the archives, but I think it's a direct change.

It you have the time today (this evening for you), we could tackle the rear end info. I am just sitting around my office waiting for an electrical contractor to replace some high voltage components. It's too dang hot out there to be watching them all the time.

If I remember right, you have already pulled your rear axle. Just grab some sand paper and start sanding through the surface rust on the back side of the drivers side axle tube near where they welded on the brake pipe clamp. Should be a 2 letter code.

From the archives, it appears you need a TH 350 with a short tail shaft. The driveshaft and cross-member will fit OK. But you will need a 2-speed to 3-speed conversion for the shifter from Shift Works.

Post # 95452 on July 12, 2007 had a lot of good info. Tranny Swap Topic

I had forgotten about the PHS stuff, will look into that again now.

Thanks for that topic, and also Shift Works... hopefully I can still have column shift.

I've made a new topic about the axle.

ST300 and TH350 use the same driveshaft and crossmember.

I am now pretty set on getting a TH350 to replace this one, but...

From Wikipedia (I know, not the best source):
"From 1967 to 1969, the Super Turbine 300 was also available on the sporty Pontiac Firebird with the overhead cam in-line six-cylinder (230 and 250 cubic inches) or small V8 engines (326 and 350 cubic inches)"
But, there were no sources/references cited.

I read that and think it is pretty accurate. I thought you had to get the 400 engine option or the HO 326 or 350 option (4 Bbl carb) before you got a TH 400 tranny.

The TH350 was first used in 1969 and then only on lower performance models. It's a good retrofit for an ST300 though.

OK so the trans I have is a ST300, original to the car.

I am still wanting to replace (upgrade) it, and am seriously considering it sooner rather than later.

I am undecided over TH350 and TH200-4R... I think it's down to the TH200-4R having a better launch and the overdrive for cruising... and whether the cost difference is worth that to me...

The TH200-4Rs I'm looking at: Bowtie, CK Perf or PATC.
All around the $1200 mark excluding a torque converter (and of course shipping which will likely be ~$700 at least plus import duties... means I'll pay ~£1500 for the trans minus the TC). The TH350 I can get a no-name rebuilt one in the UK including a torque converter for £770 with no shipping fees. Or (also in UK, but excluding the TC, and would also require a Chevy to BOP adapter plate) a TCI Streetfighter for £870 (I might have just made up my mind...

Now, my questions:

Money aside, the TH350 with a 6" tailhousing will be a drop-in replacement... whereas the TH200-4R requires a TH400 crossmember - does the different crossmember for the TH2004R still mount to the subframe in the same place?

The TH2004R would also require the rear end gears to be changed (I have a 2.56 ratio)... what about the TH350?

Am I misguided / overlooking any major issues?

Both would require a shift conversion... is it possible for either to be column shift?

Any help greatly appreciated

TH350 - You'll need to find 1969 brackets and linkage for the kickdown cable that does not exist on other transmissions. Alternatively, you can fabricate the bracket and throttle arm if you have to. Shiftworks has a kit for your shifter.

200-4R - You'll have to fabricate a bracket and throttle arm for the TV cable and you'll have to buy or devise a means of electrically controlling the lockup torque converter. You'll also have to use a TH400 crossmember that bolts to the subframe in the same place as the ST300 crossmember but it bolts to the transmission further back in the car. Shiftworks has a kit for this one too.

In my opinion your ring & pinion is too high for the overdrive 4th in the 200-4R. Will you be running in 4th gear below the torque band of your engine? Try riding your bicycle uphill in 21st gear.

OK then, thanks everyone in this topic.

I'm going to go with the TH350, it's less work (but considering the state of the car that's no big deal) but mainly for the reason of cost, I can save at least £600... useful money for finishing the rest of the car.