Thread: 700r-4

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I really have no idea, I would imagine the 400 can take the most horsepower but like I said, I don't know squat about automatics and don't like them anyway!!!! Tranny shop will warranty the 350 for the torque the engine will be making and that's good enough for me. As for the wieght, not sure but somewhere I've heard the 400 is about 30 pounds heavier. With a nip here and a tuck there I've managed to take about 130 pounds off the car, hate to give it all back on the trans and converter.....

Originally Posted by Dave Severson

I don't know squat about automatics and don't like them anyway!!!! .....

AMEN

My TH400 (which is a BOP bell housing pattern and a short shaft) weighs about 190 lbs (I think the shipping sticker quoted it at 188lbs).

From what I have heard and read, the TH400 eats up about an extra 15-20 HP over the 350 due to the extra weight in the rotating assy. The fact that the rotating assy is heavier though also makes it more durable which is the trade off (and also why I chose it, obviously not that that makes it the better choice, just why I did it). The weak points of the 350 is supposedly the sprag and the output shaft.

With a shift kit, a 350 can be built to take some torture. In a stock set-up though behind the kind of torque a big block can produce, is IMO begging for it to grenade. GM put the 400's in stock with big blocks to handle the extra torque.

In reality if an auto is going to be used for racing, an aluminum power glide is I believe, the way to roll. There is much less parasitic loss in a glide than really about any other auto and they weigh less too. They just don't have the lower first gear. But, like anything else, you would have to add some after market goodies to make them live.

I too prefer manuals if all out performance is what I am after, they don't eat up all the HP that the auto's do. Also, to me, they are lot more fun to drive as long as your not in stop and go traffic all the time...

the 700r4 was suppose to be a new, improved 400.