Tranny - 2 speed?

[Longhorn Man]

Originally Posted by chrislehr

Not sure I want that at all... guess I will just avoid 55+ until I can get a 4 speed in there.

a TH350 or TH400 will have the same ruise RPM. The final drive ratio is one ton one on all the trannys with the exception of overdrives.

[cameeks]

Originally Posted by Longhorn Man

a TH350 or TH400 will have the same ruise RPM. The final drive ratio is one ton one on all the trannys with the exception of overdrives.

I went through the same thing with mine. Power glide never even entered my mind. I changed the location of the vac. line twice and tried to adjust the vac. modulator. Even argued with the parts guy about what trans I had. Finally he took me to the back to look at a gasket chart then crawled under the truck. I looked the fool I have a 3.73:1 rear end and put a 700r4 in and noticed a jump in the fuel mileage and running 2100 RPM now at 70.

[LONGHAIR]

Quote:
Originally Posted by chrislehr
Not sure I want that at all... guess I will just avoid 55+ until I can get a 4 speed in there.

a TH350 or TH400 will have the same ruise RPM. The final drive ratio is one ton one on all the trannys with the exception of overdrives.

Andy, I was assuming that he was refering to a 4speed auto, meaning over-drive?
You are right though about the other autos, the only thing that changing to a 3 speed auto would help is that you could use a higher gear in the rear and still be drivable at low speed. 3.07 and a 'glide would be a real dud.

I don't think that it is cost effective to change both gears and transmission (3speed). Swapping in an overdrive will get you both at once. Lower first gear for "out of the whole acceleration" and overdrive for lower revs at freeway speeds...keeping the original rear gears.

[chrislehr]

Originally Posted by LONGHAIR

Andy, I was assuming that he was refering to a 4speed auto, meaning over-drive?
You are right though about the other autos, the only thing that changing to a 3 speed auto would help is that you could use a higher gear in the rear and still be drivable at low speed. 3.07 and a 'glide would be a real dud.

I don't think that it is cost effective to change both gears and transmission (3speed). Swapping in an overdrive will get you both at once. Lower first gear for "out of the whole acceleration" and overdrive for lower revs at freeway speeds...keeping the original rear gears.

so start shopping for 700r4?

[LONGHAIR]

That is how I would do it. It gives you the best of both low-end acceleration and lower RPM at higher speeds on the highway. Then you can sell the PowerGlide or keep it so you can return to stock, if you feel the need later.

[fine69]

I have a 70 parts truck that had a Powerglide. Column still in it.

You could get a powerglide tranny in Malibu's and Chevelles up until at least 1973. Have seen a couple.

[Longhorn Man]

you know what jim... you are absolutly right. I had totally misread that.

[Brad]

My Camaro has a TorqueDrive Powerglide transmission in it. There is no 'drive' gear and it must be manually shifted from 1st to 2nd and back. I've only seen 1 or 2 others like it. I'd love to have a TH350 or better yet, a 700r4, but it would ruin the originality of the car.

[Longhorn Man]

and?






lol... gotta mess with you brad!

[Brad]

sheesh, no respect.....no respect......

[67_C-30]

Originally Posted by LONGHAIR

Andy, I was assuming that he was refering to a 4speed auto, meaning over-drive?
You are right though about the other autos, the only thing that changing to a 3 speed auto would help is that you could use a higher gear in the rear and still be drivable at low speed. 3.07 and a 'glide would be a real dud.

I don't think that it is cost effective to change both gears and transmission (3speed). Swapping in an overdrive will get you both at once. Lower first gear for "out of the whole acceleration" and overdrive for lower revs at freeway speeds...keeping the original rear gears.

I agree totally! See, I'm on the other side that of that equation. I have 3.08 gears and a TH350. I'm generally satisified with the performance of the truck, but an OD tranny would make it even better on the highway and the takeoff would be slightly better. My problem with is that if I go with a 700R4, I'm going have to put steeper gears in it. 3.08's and 700R4's are so gutless at 45-55 mph that I'd rather leave it like it is because it spends much more time at those speeds than at highways speeds. If I were in shoes, it would be a no brainer - I'd go with the 700R4 because you only have to change one of the componants.

[Bob68stepside]

Power glide first gear ratio is about the same as a TH350 2nd gear. The final output is still 1 to 1. A TH350 will give you more gear at the line but will still be screaming at highway speeds. a 200R would be excellent for the quick off the line action and also be sane at highway speeds being that it is an overdrive. I have seen these in vehicles making over 500 Horse. They need a little upgrading but are fairly stout. If you end up just changing the rear gear your going to give up quick acceleration no matter what trans you run. I had a 68 chevelle with 3.08's and a glide and it 90 mph at 6000 RPM in first gear. But really soggy on the take off.