About Us

scotts66goat · 01-07-2004, 09:45 AM

I recently purchased a 66 GTO, all original except tranny. The previous owner 2nd said that the original trannys case just deterated and crumbeled. I have never heard of this, is that common? Also just bought a 66 tempest parts car that has a good tranny, but it had a 326 in it, would this have a different 1st gear? And last of all, how important to have a #'s matching trans, as this is the only thing on the whole car that has been touched. The car has been in storage 25 yrs and everything is there and complete except trans and what the rust ate.
Any and all info will be greatly appreciated, I have been chompin at the bit for 24 hrs to get on here to talk to people that really know goats. I haven't restored a Pontiac for 20 years and times have changed, and I don't want to do anything to harm the value of this GTO when its done.
I spent 8 hours yesterday reading all forums, you guys are great' and this is a awsome sight!!

Thanks,
Scott

scotts66goat · 01-07-2004, 09:45 AM

I recently purchased a 66 GTO, all original except tranny. The previous owner 2nd said that the original trannys case just deterated and crumbeled. I have never heard of this, is that common? Also just bought a 66 tempest parts car that has a good tranny, but it had a 326 in it, would this have a different 1st gear? And last of all, how important to have a #'s matching trans, as this is the only thing on the whole car that has been touched. The car has been in storage 25 yrs and everything is there and complete except trans and what the rust ate.
Any and all info will be greatly appreciated, I have been chompin at the bit for 24 hrs to get on here to talk to people that really know goats. I haven't restored a Pontiac for 20 years and times have changed, and I don't want to do anything to harm the value of this GTO when its done.
I spent 8 hours yesterday reading all forums, you guys are great' and this is a awsome sight!!

Thanks,
Scott

sleepy · 01-07-2004, 10:34 AM

I don't know about the numbers match. The powerglide casing is aluminum so YES it can crumble to dust from corrosion. I may be wrong but I think the two different gearings are the final drive and not first gear.

johnta1 · 01-07-2004, 11:26 AM

The different gearing in a Powerglide is the first gear.

The 2 speed in your Pontiacs are not Powerglides however.

They are different, called ST-300 I believe.

johnta1
Pontiac Power RULES !!!
www.wallaceracing.com

scotts66goat · 01-07-2004, 11:40 AM

you learn somthing everyday, thats why I'm here. Most of my restores have been Mopars, so I need some educating, I'm just some dumb, not plum dumb

goatless · 01-07-2004, 02:03 PM

Wecome to the boards Scott.
Is the tranny in your car now a 3 speed auto? If every thing works and it shifts good I'd just leave it in there. If it does need to be replaced you'll need to figure out what's in there as yokes and driveshaft length will vary depending on tranny.
The TH350 is a direct bolt in for the ST-300. It uses the same cross member location, yoke and drive shaft. To put a TH400 in place of the ST-300 you need to move the cross member back, use a different yoke and shorten the drive shaft.

scotts66goat · 01-07-2004, 02:34 PM

It has the st-300 now but its shot, what models and years of the 350TH will bolt in?
Thanks

goatless · 01-07-2004, 02:41 PM

Any TH350 with a BOP housing will do.
One more thing, the TH350 uses a cable kick down so you will have to deal with hooking that up.

oregonfirstgen · 01-07-2004, 02:56 PM

Hey Guys, not trying to butt in ,but if I remember right I put a short tailshaft t400 out of a buick and it bolted right in on my 67 GTO, 66could be different though. Dan

goatless · 01-07-2004, 03:09 PM

The '66 automatic was the ST-300 and '67 auto was the TH400. If you had a '67 parts car the tranny and drive shaft would be a bolt in (after moving the crossmember) into the '66.

stevep · 01-07-2004, 03:46 PM

69-79 Buick,Olds,Pontiac short 350's will be a direct bolt in.The torque conveter is the same.You will need the filler tube and a downshift cable.

The difference between inlaws and outlaws-outlaws are wanted

b-man · 01-07-2004, 08:25 PM

All of the Super-Turbine 300 2-speeds have the same gearing, 1.76:1 low and 1:1 high. You can use the 326 Tempest tranny if you want. The GTO tranny has one more plate in the clutch pack as well as using a converter with a slightly lower stall speed, that's pretty much the only difference.

------------------------------
My wife says I never listen to her, at least that's what I think she said.

scotts66goat · 01-08-2004, 05:19 AM

Thanks for the info

PONTIAC DUDE · 01-08-2004, 06:12 AM

Would like to see a pic of that 2 spd tranny as I do have a "REAL" Pontiac Poweglide that looks and is built the same as the Chevy glide. Except for the Pontiac mounting pattern. Looking for another one as a spare.

But I also have the Turbo looking 2 spd too.
For Sale

************************************************** ***************************

Build it fast, build it right, build a Pontiac.

http://PontiacDude.cc

lil64gto · 01-08-2004, 09:04 AM

Scott,

I just finished a frame off on my 64. It too had the T-300 2 speed tranny in it. I replaced it with a TH350. The tranny came out of a 67 Olds. The dipstick has been a real B#&$W, but everything else went fine. I ordered a conversion kit from Shift Works that allowed me to keep my column shift looking original, but able to get all 3 gears. The kick down is cable and the later Pontiacs will have the brakets that you can use. All in all it is worth the change over, a lot more fun to drive and a lot more performance.

Good luck

http://www.geocities.com/jims64gto

joandearl · 01-08-2004, 10:02 AM

About your trans, I also am a mopar guy new to Pontiacs. I just completed a swap to a TH400 in a '64 GP. I would recommend going to a TH350/400 in place of the 2 speed. You can keep your stock shifter, Shiftworks.com has a complete kit to convert your shifter to the new trans. I recently acquired a 455 for the GP but I have to go through the motor first. I have a pair of 6x heads(its a 76 engine) and I want to put tri power on it so it still looks stock....Good luck with the swap.

ERIC17621 · 01-08-2004, 10:16 AM

Those ST-300's are a pain. No one has heard of them (except on Pontiac boards) and finding parts (seal kits, ect.) is a hassle. They also came with a switch pitch converter/pump system, and good luck finding someone local that can rebuild that and make it work right. There is no downshift. Once it shifts, it stays in top gear. Your passing gear is just the switching pitch of the torque converter which allows your converter to slip, and increase rpm's by about 400 or so, but no real passing gear. They are more trouble then they are worth, and of yours is broken, then you already have an excuse to swap in a TH350.

Tripower: The big bad car and three little [gas] pigs!

Menu

About Us