[dogboy]

im building a 68 lemans that will have around 400 horses i would like to keep the 2 speed trans and waws wondering what performance mods that i should consider? i will be installing a posi rear end with either 3.55 or 3.77 gears. Any recommendations on convertors or shift kits that are availible and who makes these parts. I see alot of the drag racers still use the 2 speed my car will be used for weekend driving aminly but i would like to see what i 'll do at the track as well


thanks

[dogboy]

im building a 68 lemans that will have around 400 horses i would like to keep the 2 speed trans and waws wondering what performance mods that i should consider? i will be installing a posi rear end with either 3.55 or 3.77 gears. Any recommendations on convertors or shift kits that are availible and who makes these parts. I see alot of the drag racers still use the 2 speed my car will be used for weekend driving aminly but i would like to see what i 'll do at the track as well


thanks

[Steve Barcak]

Strongly reconsider your choice to keep the 2 speed (300 super turbine). It has a poor 1.76 first gear and is a bad choice for any low-modest horsepower combo. Even more so with a heavy car. You can upgrade to a 3spd auto either 350 or 400thm for little money and reap enormous performance improvements with a 2.50 first gear. Mileage/cruising is still 1 to 1 in high gear so there is little to lose. Do this, you will not be sorry! The 350 3 spd is even the same length as your 2 speed so yur drive shaft will work without any changes. Steve www.pontiacheaven.org

[ERIC17621]

I agree, for a street machine, a two speed is not a good choice. I know the guys that still run the 2 speeds in drag cars, and it is for entirely different reasons then what you are concerned about. A friend of mine runs a Camaro with a 'glide. His main reason is to save the 40 lbs over a TH350, most of which is rotational mass, but he also has a 523 cubic inch Merlin engine. He makes 950 hp without nitrous, close to 1400 with, and runs 8 seconds 1/4's (in a heavy, near DOT class car). If a car can hook, and lift the front tires about two feet off the ground with a large first gear, then why would he need a lower ratio launch? Not exactly the same as a 400 hp street application. BTW, I have a ST-300 on my GTO (street car), and plan on replacing it very soon.

As for your original question, part of the reason I have decided to switch, is that parts are very hard to find for the ST-300. Some parts are interchangeable with the TH350, but I couldn't tell you what ones exactly. The first time you need a part that is specific to the ST-300, you'll wish you had a more common tranny. If you do go with the 2 speed for any reason, get a good (read $$$, not some TCI, or B&M designed for a ch*vy) higher stall torque converter to get that thing off the line. Torque converters are interchangeable with the TH350, so you can find those at least.

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

[lil64gto]

dogboy,

The 2 speed is noisy, not much fun to drive, and really lacks anything in the line of standing start take offs.

I changed out my 2 speed and put in a TH350. Everything is the same and bolts up with no modifications. Put a shift kit in it and can get the tires to squeel going into second with out much effort.

My engine is putting out about the same HP that you are planning to build. Not sure if you have a column or floor shift, but it makes no difference. You can change the 2 speed shifter on either to a 3 speed with a conversion kit from Shiftworks. Easy to do and works great.

Trust me a 3 speed auto is much more fun and a lot more perfomance than the 2 speed you currently have. If you do put in a 3.55 or steeper you will wish you had the 3 speed.

http://www.geocities.com/jims64gto

[PONTIAC DUDE]

Pontiac powerglide, I'm interested in it.

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

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


http://PontiacDude.cc

[Blue '66]

PD,what cars/years were the powerglides used in pontiacs?

[PONTIAC DUDE]

I don't really know, but was told 69 thru 70.

I have one that was in the Funny Car that I bought off Matt Dalton. Looks identical to the Chevy glides I run now, but with a Pontiac bolt pattern and no dual pattern.
I imagine the 95% of the 2 spds are the turbine 300

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

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


http://PontiacDude.cc

[Blue '66]

I have a friend that is pulling a 2 speed from a '68 firebird,but I didn't know if it was a st 300.

[thirdgen455]

the only BOP glide I have ever see was at a swapmeet last year,and I was told it came out of a 4 banger car. I knew I should have bought that thing

[dogboy]

wow strong feelings on the 2 speed

thanks for all the info on the tranies fellas
I have to go with the 350 trans now just wanted to get some input on the differences because having a 2 speed sounded cool and different.
Ill take pics of the trans and post them hear so you can tell if its a true 2 speed and if your interested it will be for sale.

I might be interested in getting some trade work as well Ken such as heaed work if you do that sort of thing?


Thanks everyone i might actually get to drive this thing one day


Dave A.

[Randy Frazier]

FYI,

They made the Turbine 300 transmision in air cooled and fluid cooled versions. The lower powered cars such as 6 cylinders used the 300 model that had cooling holes in the transmission bellhousing case. The V-8's had transmission cooling lines. Also, as far as I know the 300 transmissions used an electric downshift switch (sort of like a TH-400) and the switch was mounted on the carb.linkage. This was at least through model year 1967. The Powerglide was a mechanical downshift that used a linkage rod from the carburetor to the transmission like the TH-350. In '69 &'70, GM also sold a cheap version of the Powerglide called a "Torque Drive". It came in some of the 6 cylinder X and F body cars with 6 cylinder engines. It was a manually shifted 2 speed. Not many people knew that the thing wouldn't shift itself so most folks drove around in high gear all of time.

[stevep]

Pontiac Powerglides came in some strippy 70-72 Pontiacs,not many,but they were there.I've mostly seen them in LeMans' but have seen 2 in Catalina's.It had a VERY long tail housing.
They all had the universal bolt bell,with the "Chevy only"bolt holes undrilled.

The difference between inlaws and outlaws-outlaws are wanted

[TigerClaw]

sorry to but in but let me ask this. Im want to keep my 326 2speed setup stock. I know everone wants to to change but im not, so heres the thing. Its just going to be a nice clean show car that I will drive to the show(not trailer). Mine shifts great just sounds like a super charger if u know what I mean. Do they sound like that? Any was I will fix the 326 with 30 over and new 400 heads, headers, cam, lifters, and 4bbl, do you think the 2 speed will be ok with a bigger stall. Any input would be great thanks.

[stevep]

Tigerclaw,all Powerglides and ST300's whine in P+N.
The 2 speed will be OK,but the car and YOU will be much happier with a 350.

The difference between inlaws and outlaws-outlaws are wanted

[ERIC17621]

Tiger Claw, My ST-300 does whine in park/netrual, not that loud though, and I can't hear anything abnormal while driving. Not sure how loud yours actually is, or if it happens while driving, but I have never heard that.
I can certainly respect it if you are set on keeping that tranny, but it makes no sense to me why you would soup up your engine like that and keep the 2-sp? Dollar per dollar, a TH-350 will be the cheapest performance upgrade possible. Hell, for the price of the headers alone, you could bolt up a TH-350, and that tranny will do more for you then headers ever will on that combo. Keep the logs, and swap the tranny. Just my $.02

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

[TigerClaw]

Good info but when things are free for the setup u use what u have. I would rather not do much to this car for I have, a 70 duster im working on and a 53 f100 that im still working on so the 66 lemans is not the one I want to go all out on. The mustang is almost done so that will free up some time, thats if im not helping my dad on his 67 GTO. BUT YOU NEVER KNOW I MIGHT CHANGE MY MINE TOMORROW..LOL

[sunfire64]

here is something you can quote me on. Having a power glide is like having a turbo 350 on steroids . mine is in a 64 and I do not intend to change it. 67 H.O. motor, 66 tri. power. 425 H.P. 2500 stall, 3.55 posi. And the front end does come up. granted a 4-speed car is the ulltimate. sunfire64

[slgenge]

Guys my 66 GTO has a super turbine 300 its ok but I am replacing it with a Turbo 400.I know a lot of drag racers use a powerglide.From what i have been told a superturbine is not as reliable as a powerglide. I want the lower first gear and the 3 speed when traveling down the Highway @ 70mph.I have also been told that 200r is a good swap also having overdrive .If the car is # matching keep the 2 speed (this is what i have done).Hope this help you out

Shawn

[lil64gto]

PontiacDude,

Here is one that is listed on e-bay. It is the real deal .
http://cgi.ebay.com/ebaymotors/ws/eB...tem=2461103327

http://www.geocities.com/jims64gto