2 speed powerglide, is it worth it? - Pontiac GTO Forum
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post #1 of 28 (permalink) Old 02-22-2011, 06:25 PM Thread Starter
 
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2 speed powerglide, is it worth it?

Hi i have a 67 lemans with the original engine and trans. I'm wondering how the 2 speed powerglide will perform once i finally get the car up and running. I've heard that some people really like the powerglide for racing but im hesitant to believe that. How is it on the freeway as well? I'm not too worried about gas mileage because i know its not going to be good anyways but will it be at a super-high rpm while going 70-80? This is my first project and im excited to get it started. Im thinking of getting a 4 speed manuel tranny instead. Any advice?
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post #2 of 28 (permalink) Old 02-22-2011, 07:30 PM
 
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Don't know how they are at freeway speeds but a lot of people raced them 'back in the day'. Look up 'Art Carr', 'Art Carr Performance Products', or 'Art Carr Transmissions'.

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post #3 of 28 (permalink) Old 02-22-2011, 07:59 PM Thread Starter
 
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thank you but i was looking for more of a personal view from someone that has owned a powerglide but thanks for replying.
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post #4 of 28 (permalink) Old 02-22-2011, 08:22 PM
 
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2 speed trans

Well as far as freeway speed vs. RPM, If you are thinking about installing a modern over drive trans, then there would be a 1000 or so drop in freeway driving RPM, a tree speed TH 350 or 400 will have the same final drive as the two speed so it would be the same there.
But the three gears will give you a performance for street driving,
Our 65 has the ST300 2 speed, the buick based trans, I would think that is what you have.
It works fine and a 60-70 freeway speed is around 2200/3000 RPM range, we are running 3.08-1 rear end.
hope this helps
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post #5 of 28 (permalink) Old 02-23-2011, 08:03 AM
 
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Sixt5 is correct. Not a PowerGlide. Suoer Turbine 300. No amount of modifications can make ST-300 "act" like a 'glide.

Drag racers use PowerGlide in LIGHT cars (under 3,000 lbs.) for best results in bracket racing. Often, 'glide cars are 1/8 mile "specialists". Only one shift... Heavier cars generally use TH400.

TH350 will literally bolt right in. Adding the lower 1st gear changes the entire "character" of the car. It will act similarly on the highway, but low-end performance is DRAMATICALLY improved, expecially when you have "tall" gears (3.23-higher ratio, lower "numerical").

If "originality" is not the primary concern, TH350 for a mild engine and TH400 (needs a bit of "adaption", but well worth it) for a "hot" motor...

FWIW

Jim
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post #6 of 28 (permalink) Old 02-23-2011, 10:09 AM
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I've owned and driven GTO's with the Super Turbine 300 2 speed...it's a strong, dependable unit, but it makes the car a non-contender with it's 1.87 first gear ratio. A switch to a TH350 will literally transform the car. I had a clean 64,000 mile '65 hardtop back in the early '80's, and it's biggest performance "drawback" was the 2 speed tranny. I had a near identical car at the time with a 4 speed, and it was a night and day difference.
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post #7 of 28 (permalink) Old 02-23-2011, 10:28 AM
 
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2 speed trans

If you do not mind the 2speed trans, the super turbine 300 is a more responsive transmission then the chevy power glide, Buick two speeds where known for good power tranfer a hydraulic and mechanical mix around a 70/30,
But as stated a TH350/TH400 is a better performer.
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post #8 of 28 (permalink) Old 02-23-2011, 03:56 PM Thread Starter
 
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thank you for all of your responses. im looking at the 700r4 has anyone installed one of these on a 326 before? There is no driveshaft in the car right now so that's not a problem. if not that im looking to put a manual transmission as well. originality is not a concern.
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post #9 of 28 (permalink) Old 02-23-2011, 04:51 PM
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A guy on the "other" forum (py forumsonline) runs the 700R4 in a bunch of his Pontiacs, and drives them literally 100's of thousands of miles. He tows trailers a lot, too. It's a simple conversion, and will net you great power "off the line" and excellent fuel economy going down the road. It's a common and prudent conversion.
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post #10 of 28 (permalink) Old 02-24-2011, 07:50 AM
 
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If wanting to go "OD", TH200-4R (NOT to be confused with TH200, a completely different "animal", and major POS) is superior to 700. The trans guys I know say to use that one, with an upgraded sun gear and shell, and it will out-perform and out-live 700 behind an engine with low-end torque. 700 was designed for small block and V6 Chevys. 200-4R will literally bolt right up to the 326. 700 will require an adapter.

RoadRageDavid's '68 Firebird ran a "Level 10" 200-4R for threee years without issues, 500-plus HP, close to 600 lbs. of torque, clocked at least once at 200 MPH.

Either will deliver the OD you're looking for. Chevy guys "like" 700 better for obvious reasons. That's why there's so much more "info" out there about it.

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