My Tubo 350 was just rebuilt...shift kit, etc. Motor 450 hp. Trans guy guaranteed to 800hp!
Now that I can drive it I realize an overdrive is necessary. I wish I would have known that before I had the 350 Turbo rebuilt.
I'm looking at a built 700r4...but...it will have issues...
TV cable instead of vacuum modulator.
My Lokar shifter will have to be replaced.
Trans will have to be removed and replaced.
Lots of Trans Fluid.
New trans dip stick.
Additional trans cooler.
Speed-O cable issues.
Shorten drive shaft.
Yaa Da Yaa Da Yaa Da................
Gear Vendors...remove and replace tail piece, shorten drive shaft, minor electrical.
Has anyone done this?????

I have a 383 with a 700R4 in my fifty mercury. I bought the tranie from Phoenix Transmissions. The tv cable is not a problem as long as you follow directions. Mine has a 2500 rpm stall converter. You have a cooler in your radiator, I don't see the need for an additional cooler. Phoenix has a good warranty I think I paid around 2500.00 for it.

Why not at built up 2004R? Same size basicly as the TH350. So that takes away some of your issues

Actually i would love to see someone use a gearvenders unit on a th400 or 350. Why not have the stronger three speed with an add on overdrive?

I would check into a built 2004R. $2,600 for a Gear Vendors. Summit has a 2004R with 450hp rating for $1,430.
http://www.summitracing.com/parts/PMA-PA20102

The Summit 2004R may have a 400Hp rating. Here's another one for $2062 with a 500HP rating. Same physical dimensions as the TH350
http://www.transmissioncenter.net/200-4r.htm

I haven't heard about the 2004r...has anyone 3rd Gen done it?
Need TV cable?
Need shorter drive shaft?

ok ima gonna be the dumb one.... whats a Gear Vendors unit??:???:?

http://www.turbobuick.com/forums/transmission-talk/

ok ima gonna be the dumb one.... whats a Gear Vendors unit??:???:?

An add-on overdrive unit.
http://www.gearvendors.com/

I have a 200R4, and when it came crossmember time, the ads I saw said the 200R4 and TH400 used the same crossmember. Point being I think Allies79 is mistaken. You'll have to alter driveshaft lenght either way. The plus side of the Gear Vendors unit is you get 6 speeds, not just 4. Pretty pricey though.

A gear vendors is the stuff!!!! I want one, I gotta have one but I can't afford one!!!!
I seen a used one off a show car for $1000.00, too much risk for that knida of money.
All I want for Christmas is a gear vendor, O.K. may world peace then gear vendor, O.K. maybe a million dollars, world peace then a gear vendors. (Steve Martin Christmas wish!!!):nanawrench:
Donny

I've worked on a couple of vehilces with GV units and will say they are a very heavy duty (think RVs and Diesel trucks), reliable unit that work very nice. Installing it to the transmission is straight forward and simple.

There is a down side however (besides the price). The big one is the size.... they usually requires a fair amount of transmission tunnel modification in order to fit. If you look closely at the unit there it will sit is usually where the trans tunnel narrows down.

What sticks in my mind is the C4 vettes with 4+3 overdrives. I assume they are similar. I maybe wrong.

I would like a gearvendors, but for how much more can I get a t56. So wont go GV.

A 2004R is available to handle a lot of power, but it's big bucks, from Gearstar. Their site has all the details.

Interesting Transmission Swap information

General Tranny Swap Information:

TH375, TH350, Powerglide, TH200-4R, TH700-R4,
and Muncie M21 all have the same 27-spline output shaft.
TH400 has a 32-spline output shaft.
TH350 and TH200-4R use the same yoke.
TH700-R4 is 3" longer than the TH350 short
tail.
TH700-R4's rear mount is 2" to the rear of
that of the TH350 short tail.
Swapping from a TH350 short tail to a TH700-R4 will require shortening the driveshaft 3".
TH350, Powerglide, and M21 all have the same length and output shaft spline count - therefore, no driveshaft mods required when swapping.
TH350, M21, TH200-4R, and TH700-R4 all use the same tranny mount,
but TH200-4R and TH700-R4 use metric fasteners (M10 x 1.5 x proper length).
Shims may be needed when swapping TH200-R4 in place of TH350 (or
any tranny swap, for that matter) for driveshaft phasing.
Transmission mount or crossmember may need to be relocated fore
or aft for any given swap.
TH200-4R and TH700-R4 have lock-up torque converters (from the factory)
and thus no top gear slippage when locked.
M21, TH350, and Powerglide all fit the '68-'74 Nova without modifications, and I'd imagine the TH400 would, too, since they were available from the factory.

WOW!!!!!:nanawrench:
Thats alot for my little pea brain to take in.
Thanks for the info.
Donny

I copied this from another Chevy forum:

Oh, and I forgot... the 200-4r is a direct bolt in for the 350. You'll have to move your crossmember back to the other hole in the frame, but overall length is the same and you can use the same driveshaft. Not true of the 700r4.

There is a lot of information on transmission swaps on other sites, if you search. I stuck with a rebuilt th350 myself because of the rear axel ratio in a 305" to 350" in a '79 swap myself..... if money wasn't an issue I would have gone with the 200 4R and installed a lower rear gear, I did a lot of research....but enought money is the age old story isn't it.

a 2004r is a direct bolt in????? i am sooooo gonna keep my eye out for one now.

the 2004R is the same length as the TH350 and uses the same yoke spline so the only reason the drive shaft would need to be modified is if the rear end was also changed to an 8.5 incher then the drive shaft would have to be shortened an inch.I think for those needing a strong alternative to the three speeds might want to look at the 4L80E also.Bsically its a TH400 with an overdrive added on of course its also electronically controlled so an aftermarket box is required or with some slight trickery it can be used as a full manual valvebody---(my way).................Dan


P.S. another thing about the Gear Vendor unit---you can't get parts to repair it from anyone else and they won't sell them to you so its a 2000 dollar repair if you injure your unit---ask me how I know.

The wrecking yards say that the drivelines for the turbo 350 and 200r4 are the same in G bodies.Here's a note check out Monster transmissions on line sometimes they get some really good deals on package deals, that being said if your building a cruiser I would go with the 200r4 if your going race it stay with th350 and add the gear vendors overdrive in any case it comes down to what you want and how you use it. Good luck.

Didn't notice what an overdrive unit costs. There is Gearstar, with transmissions for various power levels.

http://www.gearstar.net/transmissions/more.php?unid=53

A 200R4 capable of handling 400 HP should work, and the price may be better than a Gear Vendor unit when considering all the mods to get one bolted in.

And the Gearstar has a transgo shift kit (the best in my opinion) and includes the converter, and even a 20,000 GVW cooler.

I bought a turbo 350 from Gearstar,I don't know about their 200R4, but the 350 works great. I picked mine up at their shop and got a tour of the facility. They have the cleanest, most organized shop that I've seen!! They have 1 person do the complete job on a rebuild, and they take the work seriously. The man that did mine has done trans work since 1974, it's the only job he's had since high school. As steelybill stated you also get a converter and a cooler,and they guarantee their work (in writing). I'll buy another one from them as soon as I start another project.