4bblC4

Well, I've heard so much good and bad about the 700r4 tranny, that I just couldn't make up my mind. But being that my motor already puts out over 500hp and tq, and I want to run anywhere from a 150-200 shot of juice, I wouldn't be able to quit worrying about the 700r4 breaking. AND it's gonna cost over 1800.00 in parts to beef it up enough. SO, I was looking on here last night at the threads from guys that have run a TH400 and a gear vendor. The swap seems not that bad at all, I can fabricate the torque arm just fine.

However, right now I don't have the dough to buy a gear vendor, so It'll just be the 1:1 and my 3.07 gears for now. Maybe in the future I'll be able to afford one, and I'll shorten the driveshaft and fabricate that torque arm.

What my question now is, how long is the th350 as compared to the 700r4 if you don't include the tailshaft? I'm asking because the tranny shop here says that I might be able to mount the 700r4 vette tailshaft on the TH350, if the TH350 has the right length output shaft, not the longer one or whatever.
That would save me having to fabricate the torque arm and shorten the driveshaft if the overall length was the same, and thus would save me some time and band-aids.

Does anybody know if the 700 tailshaft WILL bolt to the 350? and if so, what length tailshaft should the 350 have on it to begin with so the output shaft will be the right length for the 700 tailshaft?
Also, even if I can run the 700 tailshaft, will I still have to make a torque arm and shorten the driveshaft, because the overall length of the th350 will be longer?

sorry for the long windedness. Thanks guys!

4bblC4

The reason why I'm gonna run a TH350 is cuz my friend that owes me some favors has one that's really built, I just don't know how long his output shaft is yet.

I would run a th400 tho, if I could.

Corvette Kid

You could always have your drive shaft length adjusted to fit. This doesn't cost a whole lot. Your launch will suffer because the low gear ratio in a TH350 is significantly higher. Also the obvious MPG penalty w/o overdrive.

4bblC4

I know I can have the shaft adjusted.... I'm just wondering if anybody knows the lengths of the trannys

I actually just got off the phone w/ PATC ( www.transmissioncenter.net )

They're gonna hook me up with a TH400 w/ a 9" shaft, and I'll have the shaft shortened a few, and make that torque arm.

Anybody have a gear vendor they wanna give me?

thanks corvette kid

CFI-EFI

With the TH350, all you have to do is make up a spacer/adapter to install the Corvette 700R4 tail shaft housing on the TH350. If it is the correct length, the "C" beam bolts right up. I'm not sure about the drive shaft, but for this kind of project, that's pretty minor.

RACE ON!!!

4bblC4

Thanks cfi-efi!

I don't think it'll be the right length if I just put on an adapter/spacer for the 700 tailshaft. If it was, the c beam and driveshaft would bolt right up tho, that'd be nice.

I now the th350 is a little bit shorter, so I'd need the longer output shaft th350 (9") and then put the spacer/adapter on that for the tailshaft. then I might get lucky, but even with the longer output shaft, I don't know how it'll match up to the driveshaft/ c beam.

I'll probably just end up fabricating the c beam and shortening the driveshaft. I think I'm gonna run a th400 anyway.

suprised more people haven't done this swap.


http://temp.corvetteforum.net/c5/bob...nversion.shtml

learned alot from that site!

CFI-EFI

If you make the spacer/adapter the right length, it WILL bolt up to the "C" beam. It's been done before. I even think one of the trans specialists sells the spacer/adapter. If I remember correctly, it was under $100.00.

If your mind is made up to use the TH400, that's a different can of worms. I've seen specially made up 400 tail housings to take the "C" available for about $1000.00.

RACE ON!!!

4bblC4

screw that!

that's why I have a welder.

Lone Ranger

carb (judging from your forum name) and a TH350... ... you're taking that car Old School, huh?

mackeyred96

I like old school, you may even see a 350th and carb in mine someday.

4bblC4

thanks guys!

actually, I went the carb route originally because I had the parts, and didn't want to buy a miniram or superram.

But then as I thought about it, I thought that it would be cool to take a car that everyone thinks of as fuel injected, and when I pop the hood, they see a carb.
Kind of a cool trip to see a late model car w/ a carb. for the first time.

So old school it is! LOL!

thanks again tho, most people on the c4 forum tend to kinda frown on carbs. I haven't been flamed or anything, but it's not a really popular swap.

But back on topic, I've changed my mind (again). I'm going to run a th400 w/ a 9" tailshaft, fabricate my c beam, and shorten the driveshaft a couple inches.
Then in the future, I'll get a gear vendor, and redo it all over again, fabricating the torque arm and shortening the driveshaft furthur.

hippy

If you are going to throw a power burning TH400 in with fabbin why not do a 4L80 trans. You do it once and do it right and make the trans one less thing you have to screw with in the future. Just a thought.

cv67

If you are running 500/500, definitely go Turbo 400. Those are hard to break!

4bblC4

.... know what you mean, hippy..... I'd love one of those.

unfortunately I don't have the money at this point, but I do have a powerful motor that likes to eat transmissions.

I'll just run a GV or a US gear V2OD in the future, and end up spending as much as a 4l80e swap, but over a longer period of time.

hippy

There was a guy in one of the Corvette mags I believe from The Windy City with a blue C4 and it had some sick motor and he did the conversion to a 4l80.
I know how finances definitely are a major decision maker when it comes to parts.
or should it be this

JAKE

I installed a Gear Vendor behind a built 700R4 in a friend's 86 and, MAN was it ever a tight fit! Drive shaft ended up being about as long as my thumb. LOL

Jake

Fubar569

a GV behind a 4 speed tranny? that'd be like, an 8 speed now right? what's the cruising RPM in OD with the OD (GV)?

4bblC4

sheesh! a GV behind a 700r4? that's a .70 overdrive, and the GV is a .78........ WOW!

rpm's would be at like 500 for cruising around in od/od for crying out loud!