Thread: Which tranny?

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I'm building a street rod and unsure of which tranny to use. I'm an old school guy and like the sticks but maybe too old and considering going with an auto, so my question is should I use a 350, 400, 700R4 or ? The rear gear I ended up with is 4:11, sbc around 450hp. Any thoughts would be appreciated thanks

I would go with the 700 or the 400. the th350 could easily be damaged by the 450 hp.

Whats the weight of the rod? Weeked cruiser or daily driver?

Around 2900lbs, it's going to be a weekender, I was wondering if the 4th gear on the 700 was overdrive or not because of the 411. Thanks

Here's a chart showing the gear ratios of all popular transmissions. With a 4.11 ring and pinion, the first gear on the 700R4 will be pretty much unuseable at 12.57:1, unless you're trying to climb trees with the car. The drop from 1st gear to second gear is pretty severe also, going from 3.06:1 to 1.62:1 on the gear change. So the motor would be screaming in 1st gear with the 12.57:1 final drive, then drop the r's way down with a 2nd gear final drive of 6.65:1. 4th gear overdrive final would be 2.88:1, so that would be ok for cruising.

TH400 might be my choice for a weekend driver if I were not concerned with fuel mileage. It's a pretty much bulletproof trans that will give you a 10.19:1 first gear and a 4.11 final drive.

http://www.oldengine.org/unfaq/leadfoot/trans.htm

I'd go with a Turbo 400 if you have room. I have a t-350 and 405 hp with out problems so far.

Originally Posted by techinspector1

Here's a chart showing the gear ratios of all popular transmissions. With a 4.11 ring and pinion, the first gear on the 700R4 will be pretty much unuseable at 12.57:1, unless you're trying to climb trees with the car. The drop from 1st gear to second gear is pretty severe also, going from 3.06:1 to 1.62:1 on the gear change. So the motor would be screaming in 1st gear with the 12.57:1 final drive, then drop the r's way down with a 2nd gear final drive of 6.65:1. 4th gear overdrive final would be 2.88:1, so that would be ok for cruising.

TH400 might be my choice for a weekend driver if I were not concerned with fuel mileage. It's a pretty much bulletproof trans that will give you a 10.19:1 first gear and a 4.11 final drive.

http://www.oldengine.org/unfaq/leadfoot/trans.htm

If He wants overdrive the 200R4 is not a bad choice,check out Art Carr's site also gear ratios are better spread than the 700R4.

Agree if you want overdrive go with the 200R4, if not the 350.

www.bowtieoverdrives.com has a lot of info. That overdirve will make the car a lot more pleasant to drive around.

Pat

you dont need a turbo 400 those are for trucks, and heavy cars. know plenty of people trans braking t-350's in novas and yes chevelles and malibus and have done so for years 4-6 with no problems. use a t-350 if your going to use a 3 speed auto its plenty strongfor a light streetrod and 450 horse will not eat it up.

What does age have to do with it!!! Dang man, if you like 4 and 5 speed transmissions, put one in there!!!! What the heck is wrong with a 3 pedal car anyhow??? Even Hot Rodders are getting too dang lazy to shift??? Geez, do it the way it's fun, don't be shiftless!!!!

agreed ^^............

sorry gasser. i was told wrong information.

sometimes it happens now if i was building a monte carlo like yours yes i would use a turbo 400 simply because its a heavier car. but in a light streetrod keep it light

just think of how many drag cars use powerglides these days, talk about taking a beating getting transbraked at 4500-6500 rpm and wheely-ing a chevelle or a camaro up on the back bumper. ouch!

thanks gasser i will remember that. learn something new every day.