trevosaursflex

I have 89 GTA, it has a 5.7 with a 700r4, i have the option to put a 350 trans in it. Just wondering which one can perform better.

03_z

I would stick with the 700r4. You would really miss overdrive.

Ron U.S.M.C.

I agree.
If you want to run a 3.42 or higher rear gear ratio and still want to drive at highway speeds (around here its 65 +) for a sustained amount of time I would stay with the 700r4 with its OD.

They can be built to be "very" strong units.

sofakingdom

iTrader: (1)

Define "perform".

Not sure you have a clear idea yet about "option to put". It's not quite exactly a bolt-up. Not impossible or anything close, of course; just, a bit, ..... invasive.

What is the intended use of the car?

trevosaursflex

I have both transmissions and both are ten bolt. I guess I'm wondering which can be geared better? The car will mostly be street driven with the occasional trip to the strip. I know I'm going to want the overdrive for daily driving, but what if I just got taller gears for the 350?

sofakingdom

iTrader: (1)

Transmissions aren't "ten bolt".

You can't really change the gears (ratios, anyway) in most automatic transmissions; at least, not for a price that most of us (there are a few of course) would find acceptable.

Sounds to me from all you've said, like there's no reason for you to hack up your car to put a 350 in it. WAY too much maze, WAY too little cheeeeeze at the end.

Night rider327

iTrader: (13)

The th-350 is a bolt in swap with aftermarket parts, but in your case there is no reason to go th-350.

The 700r4 has a deeper 1st gear which around town, red light to red light you will love, also has the over drive gear.

The th-350 is lighter, and stronger, but no OD and not as deep of 1st gear.

Unless you have a 450+ HP engine I see no reason to swap out to a th-350..

Keep your 700r4, I wish I had one in my V8 S10! I have a th-350 in it, cause that's what I had laying around to use.. In the future when the money is there I will put a 700r4 in it.

My camaro, I have a th-400 in it, wish I had OD, but hard to get an OD trans that will live with 500 HP... I'm looking into a gear vendors unit or maybe a 4L80E with a stand alone controller but thats way in the future as both are high dollar items

AlkyIROC

For daily street use, a 700R4 with a low 3.xx ratio in the diff is a very good setup. The low first gear in the transmission allows you to get moving quickly with the poor ratio in the diff and the OD gear combined with the diff gear gives very good fuel mileage. The downside however is the very wide ratio between first and second gear. During a WOT shift, the rpms will drop below the powerband after the shift and a slight performance is lost as the engine is trying to get back into the powerband. Going too deep in the diff gear like using 4.10 can create excess torque in first gear and can easily overpower the tires. With first gear being so low, using a deep diff gear means you're in first gear for a very short period of time before the transmission needs to shift.

A TH350 is smaller, lighter, has a better gear ratio however it lacks the OD gear which everyone wants for fuel economy. Internally, they're about the same strength but the TH350 has less moving parts without the OD gear so less things can break.

A long tailshaft TH350 normally found in pickup trucks and vans makes an easy conversion since it will use the same driveshaft length that the 700R4 uses. A manifold vacuum line needs to be run down the the modulator valve so that the transmission can upshift. You'll also need some sort of conversion kit since the trans mount is in a different location plus the third gen torque arm won't have a place to mount on the tailshaft. An aftermarket torque arm with crossmember can make the swap easier.

If you're after good performance with good fuel mileage, stick with the 700R4. If all you want is good performance then go with the TH350. GM put that transmission in millions of vehicles so it will work just fine without an OD gear.

Another option is doing a 200-4R swap. It has similar gear ratios to the TH350 plus has an OD gear. The transmission was used in vehicle like Grand Nationals and is stronger than most people realize.

krisner89

Got a 350 in mine. Works great for how i drive it. Back roads and cruising town for some competition. I'd prefer it over a 700r any day just cause the ratios are even. Got a 700r in my truck and hate the 1st to 2nd gear shift. Then again one time I'd wish I had OD. Was going down highway with a couple girls to a bar and you had to yell just to talk to one another. Engine was screaming.

roadthrills

I agree with Knight. And hey Knight, I have the 700r4 in my V8 S10 Blazer and it's been my Daily for 70,000 miles. The 700r4 is great with 3.23 or 3.42 gears even at the track. I just short shift first at around 4500rpm, then wrap out second to 5800.

Ozz1967

iTrader: (4)

I agree with AlkyIroc, stick with the 700R or go with a 200R that they used in the Grand Nationals and I believe in the TTA. Also, early 82 and 83 Models used the 200R.

AlkyIROC

82 and 83 third gens used a TH200c, not 200-4R. Completely different transmission. 3 speed and not very strong.

Night rider327

iTrader: (13)

Cool deal. My '88 S10 is my DD as well, so the 700r4 would be a much better option for me. Mine has a 3.42 gear

Ozz1967

iTrader: (4)

Hmm...I stand corrected. I always thought it was a 200-4R that they changed to the 700R4 in 84.

sheikss

Stick with the 700. You can find gears to change/cure the 1,2 shift gap. If you make enough power to kill a 700 then it is time to go 4l80. As for 700 strength, buddy of mine ran 10.6 without much effort in his full weight street car on the bottle. Then went turbo and the trans was doing just fine.

1984ttopz28

I'd stick with the 700. I have a turbo 350 in my 3rd gen camaro, almost everytime I drive it I wish i had an overdrive. At 60 my rpms are at 3500 and if you go any great distance the motor gets a little warmer than I like it to. But the guy i bought the car from did a hack job of putting the tranny in. Welded the trac bar to the trans crossmemberr so when I finish building the rear end thats next on the list. Get a new transcrossmember and a 700 with a shift kit. Things should roll a lot smoother