TH400 vs 2 speed

Ok I am sure somewhere this has been asked, but I am thinking of changing back to a powerglide(if thats what they are called)

Reason one, less shifting.
Reason two, stronger transmission.
Reason three, less weight.
reason four, not sure I have a 4th...lol :Brow:

Anyways, I would like some opinions and facts of the differences. And I am sure some actual experience. I am sure I will speak to Bob Mackley and Jeff Ketchum here locally as well.

thanks

 

I'm pretty sure that the Buick 2 speed, Super Turbine 300, is Not the same as a powerglide. The actual powerglide is better and stronger, also the actual 'glide works best when the car weight is less than 3300lbs. (and that's on the heavy side, 2800lbs. is probably ideal). How much does your car weigh? Is it a race car?? I wouldn't waist the money to upgrade a Buick 2 speed, if car is heavy, and raced, there's no subsitute to the th400. If just a street car, how about a mildly upgraded th350.
I thought about putting a glide in my '65 race car, but it's heavy so it was better to upgrade the th400 to the max.
Gary G

 

stock factory for my car is 3199. I have dropped weight and added some, it will be weighed this year for the weight it is now.

It is a street strip car, about 75 street and 25 strip, but I plan on doing quite a few upgrades to make it at least 50/50 or 25/75.

I hear the 2 speed is ALOT better, and drains alot less power than a 400. Is it 40% of power is lost going through a th 400?

 

I am willing to see, but all is in the air, trying to make a beter street strip car.

I added you as a buddy on AOL, maybe we can discuss it more larry..

 

If you are going to use the car as a street strip car, stay away from the powerglide. The turbo 350 and 400 both have a steeper 1st gear and are actually built tougher internally. The ones that you see in more full on race cars are modified with aftermarket input shafts ,gearsets etc. To get a heavier car such as yours moving you would also need a looser converter to get the car to leave--more heat on the street.
A built 400 is tough as nails and will simply accelerate the car quickly vs powerglide because of its first gear and less of a drop between shifts.

1.82 first gear is actually a 6 cylinder piece (1.76 is stock v8)
On the street you would have to do aftermarket valve body for PG--period
With either first gear --rear gear change coming --again to make the car accelerate
your car If it were a 66 Chevy II with a aluminum head small block I would say sure but a torquey big block buick --I wouldnt.
good luck either way
George

 

OOOOOOOOOOOPS!!!!

Sorry, When I asked this I omitted the fact that it would be aftermarket. The th400 is not stock either, it was built by CK performance.

I will have the powerglide/2 speed built as well, cause eventually there are quite a bit of stuff I would like to change on my car.

So shift points and gear ratios are not really in the picture yet.. But will be in the near future, sorry for the confusion there...

Keep up with the replies..

 

As I mentioned, your car is too heavy for the glide, and as mentioned the th400 or 350 will work better for any street driving. I wanted to do a glide, so I talked to an excellent trans shop, they talked me out of the glide because of the cars weight, and the ratio issue to get that weight moving, which someone else already mentioned.3199lbs for a '67 Skylark, sound too light.If you're going to weigh it, I'd do it just to know , but the car is still to heavy for a glide.
Gary G.

 

So would the st 300's (2 speed) in the 64-67 Sport Wagons, that weighed around 3800 pounds, burn up the stock trannies?

 

Stronger transmission? I think not. The t-400 is way stronger than a power glide or t-300. The power glide and t-300 use the same basic internal components, there just is not alot to choose form with the t-300 as far as shift kits, tranny brakes and such. The vlave bodies are completely different. The t-300 uses a better input shaft than the glide.
As stated, in a pure race car situation, light car, a 2 speed can be faster, but in situations I've seen, the 3 speed will often et better, but the 2 speed will mile per hour better.
40% power loss through a 400? Come on now. I wish I could find the person or persons who spread this information, I don't know where they come up with it. Jim Burek

 

Thanks Jim... I wish I knew more factual info myself, would be nice to shut them up.
So many people run their mouths about stuff they know nothing about, instead of just not saying anything, they say too much.

Thanks for the info, looks like a better gearing in the 400 is what I will be going with then.

Its a stage 2 tranny from CK performance, I will be talking to them here soon about the actual gearing it has, and then start calculating possible better gear ratios..

thanks again for your help

 

Jess, the factory first gear ratio in a t-400 is 2.48. Be careful of aftermarket gear sets though, They are not as strong as the factory set-ups. Jim Burek

 

So far I have a really nice tranny, the TH400 I got from CK, The only prob I am having with it is the speedo cable gear does not work.

I hear that there are two types of housings that are in 400s, and two types of gears, and I must have the wrong one..

Any thoughts there?

As for the 2 speed, and being still new to buicks, I know how much people brag out the PG, and I made the assumption about the t-300 I think someone called it.

Thanks again all for your help. :TU:

 

I had a neighbor that had a 79 Mustang that WON Fast Ford at Ennis in 2001.

It ran 10.002 on a 10.00 dial in.
It would run mid 9's but didn't have a net and he didnt have firesuit pants so he had to short-shift it to keep it at 10.00 for the meet.

It used a Powerglide without issue.

It was a perfectly streetable car... 572 c.i. all motor.

Frank

 

Jim
do you have an estimate for how much power is lost through the trans? i know i've seen like 3% for estimates on slippage between the rear wheels and the flywheel but i have no idea what that corresponds to in power consumption. and of course, slippage isn't directly related to power consumed by the tranny anyways...