My 700r4 needs rebuilt. Instead of rebuilding it the guy is going to install a th350.

Performance wise, is the th350 better. I know the 700r4 are mainly for economy. But will the th350 make my firebird alittle faster?

 

unless your 700r4 was slipping badly the th350 will not make it faster. actually the 700r4 has a lower first gear.....so it will accelerate of the line quicker with a 700r4.....plus you will loose your overdrive which will suck on the highway....I know th350 are cheaper to build and rebuild, but 700r4 can be built to handle alot of power....might be better off in the long run. Plus when you swith to th350 you have to change driveshaft and add an adapter to mount torque are to transmission...hope this helps...

 

Here are my options.


Put a turbo 350 for 500$ plus a shift kit in my firebird

Or put a used 700r4 with a 3 year warenty. for 450.

What do you think i should do. I want to deside within 2 days
so any information will be helpfull.

 

I would put the 700 in, if you do much highway driving, you will miss the overdrive. I just got done switching mine over to the 350, and I miss my overdrive, but it will only be driven on short trips.

 

My car was a daily driver until i baught a new car.

I am just going to build it up and sink more and more into it.

I want to use it for weekends and the strip. So i wont be doing too much high way driving.

would the turbo 350 be better for the strip and street racing
Or would the 700r4 be.

 

I think I would go with the 700r4......

 

TH350 would be better for the strip....plus stall converter are alot cheaper, but I think you will miss the overdrive.....With the over drive you can get away with running 411 or 373 rear, which will be big improvement....

 

This weekend I'm putting 3.73's behind my th350,as mine won't see much highway driving. Why not spinn the s**t out of the motor, see what it's made of, sounds like fun.

 

What are you getting for $500 besides the transmission and the shift kit?

 

LOL@corky.....Ive been there....then I built a 406...torque monster....I had a street car with 513 gears once...never had a tach in it...probably would have scared me to see what rpms that motor was turning...lol

 

He is going to put the th350 plus the transgo shift kit for 500.

For now thas all im doing. I just baught a chvy corsica to be my daily driver so i can build my firebird up.

FOr about 3 months thats about all im getting. I have 5100$ including getting my trans. fixed.

i think im going to use the rest on collage. I start lincoln Tech in july.


I'm might use alittle of on my car.

I dont want a gear for my car because it is not possi.

I also need some exhaust wrap so ive got to spend 30$ on that.

Would a stall be a good idea? Would that help?

 

What I mean is, are you getting the parts you need to put that thing into a thirdgen too, or just the transmission?

 

He is taking the 700r4 out and replacing it with the turbo 350 and he is suppling everything for 500$

Transmission + Labor = 500$

Thats a pretty good deal, he is building my friends 91 firebird.

He put a 355 in a v6 firebird with a stall 3000, 4:10, Turbo 400

Nice A** manifold and some pretty big tires for like 2000$

I could be wrong about that price but it is some were around there.

He is really really old and really smart.

 

and what so great about the over drive? Why would i miss it so bad? I'm sorry for the stupid questions but im learning.

 

The overdrive gear and locking TCC in the 700R4 let you cruise at lower RPMs using less gas.

 

Overdrive is nice on the highway. If you don't do a ton of freeway driving I wouldn't worry about it. My car was to impractical to take on trips even with a 700r4...so going to a th350 won't be that bad.

I am having a hell of a time getting the pan to stop leaking. Its almost stopped....cept for 1 spot on the corner under the modulator valve. I am getting angry.

 

yeah, I was told the 700r4 was so good because of the gas millage.

I was also old the turbo 350 would give my car a faster take off than with the 700r4 because the 700r4 was mainly built for gas millage.

I just want my car for the strip and weekend. But if the 700r4 is just as good at the strip as the turbo 350 than i'll just get the 700r4.

 

Stock for stock a th350 is stronger.

Built for built they are both strong. 700r4 has a better first gear. That and OD is its main advantages.

A th350 is lighter if that matters to ya. And torque converters are much cheaper.

 

It also has a worse second gear, which is what kills it at the track, although with the right converter it's not as big of a problem. For all out drag racing, a TH350 would probably be better. If you want overdrive with better ratios than a 700R4, there's the 200-4R.

 

Is a shift kit hard on a car?

My brother told me there is a way to do the same thing as a shift kit, he said you can block something off or something. I forget now.

I dont know, but as hard as your car shifts with a shift kit in it wouldn't it be hard on it?

 

I haven't driven mine much but the 1-2 shift isn't nearly as bad. But I have never had a good 700r4 either. Both of mine seemed sick from the start.

 

You can block the accumulators, which is essentially what the B&M shift improver kit does. This is an excellent way to shorten the life of the transmission.

A TransGo shift kit fixes a few design defects without changing the shift feel. If you want it to shift harder, you can add a TransGo reprogramming kit.

 

If i was racing my mirror image.
700 would get the 350 in 1st gear, but the 350 would hit 2nd and 3rd gear and pull enough to pass the 700r4?

So basically the turbo 350 is faster stock for stock.

But... The 700r4 can be built to hold more power in the long run, not to mention the OD.

But, the used 700r4 could also go out on me in 3 or 4 years. Or even less, the guy could not garuntee any thing, and the most he could do is MAYBE a 3 year warenty.

The turbo 350 is new and would probably last longer.

Who says Go with the 350 Turbo?
Who says 700r4?

One thing i found out with both firebirds that i have owned.
When i torque it up on take off it spins more and is slower.
with a stall it wouldn't spin as bad when i launched?

cause i would like a stall and the shift kit put in. like a 2400 stall.

 

When I did my TH350 swap I got the trans fresh rebuilt for $275 plus my blasted 700R4 core. It was a longtail so I was able to re-use the stock driveshaft. I used a Hurst changeover kit, that was $80. For some reason my kit didnt come with the crossmember relocator pieces or whatever, so I also bought a crossmember adding more to my swap. If my Hurst kit had come with everything (I found out after the fact) then I could have completed the swap for around $400. I'm really happy with my TH350, I've had 3 700R4's fail me, probably not because they were weak, but because the previous owners didnt service them regularly. But still, the TH350 is alot better for my application. I flog the crap out of that tranny and it never breaks.

Definately get a shift kit, regardless of which transmission you go with. Raising the line pressure will cause less clutch slip when it shifts. IMO this will make the trans last longer unless you're making too much power or the stall is crazy.

 

I think a th350 could be built to hold more power.

As for racing your mirror image that is a close one. 3rd gear on both trannies is the same. 1.0. The th350 may edge you out by the end of 2nd not sure. It would probably be to close to tell.

I say go th350 unless you plan on road trips.

 

The 700R4's 3.06 first gear will get you moving out of the hole faster than the TH350's 2.52, assuming that traction isn't a problem. The 700R4 will also hit redline sooner though, and then you'll be into the 1.63 second. The change in ratio in many cases is enough that you'll have to run beyond the powerband in first, but the RPMs after the shift into second will still be below the powerband.

 

Thanks alot, i have desided the th350 is what i want.
The used 700r4 will probably mess up in the near future.
And for almost the same price as the used 700r4 i'm also getting a tranGo shift kit.

i have one more question, I baught an adjustable fuel pressure regulator and gauge. Is that hard to install?

Here are some pictures of my firebird. Also some pictures of the 89 firebird that i totaled.


http://www.cardomain.com/memberpage/781526

 

I took my car in today and guess what, i got the 700r4. I get it back thursday.

The guy said it was the best idea. He is also putting a stall in for me. He is doing it all for about 500$ thanks for all the help i have learned alot.


Since it is used should i take it easy on it for a little while?

Cuz i want to go to te strip.

 

No need to take it easy. I would drive it around a day and make sure it doesn't make any horrible sounds and shifts ok. Check the fluid to make sure its nice and red, and the proper level. Then do whatever you want to it.

 

well i would take it easy..... not saying it is a must..but i would have to build confidence in the trans.