Dean_Fuller

Been doing a ton of reading and just got off the phone with Monster Transmissions in Fl. I currently have a 400 transmission. I THOUGHT a 200r4 would be a direct swap with no modifying the drive shaft or cross member. What I am now hearing is the 200r4 only swaps with the 350 trans and the 400 still will require shortening the drive shaft and modifying the cross member. Monster Transmissions suggests I use a 700r4 as I will still have to mod the drive shaft and cross member and its a little cheaper.

For those that have done the auto OD swap...
What trans did you go with?

What trans did it replace?

Did you have to shorten the drive shaft?...cost to mod or replace???

Other expenses associated with this change that no one asks about until its too late???

I am getting a price from Monster with everything I will need stage 2 700r4 for just south of $2100.

I am still unsure of the 700r4 verses 200r4...the only 700r4 I have owned was crap in a 1987 Trans Am. Rebuilt 2 times in the short time I owned that car for a total of $2400 back in the late 1990's..

Another issue is my rear gears a 3.08...I was concerned about gear hunting in town but was told that is not and issue. I have no plans to swap rears...I want drivability, minimum motor wear and gas mileage...don't care about burning tires.

7T1vette

You can put 700R4 or 200-4R into your car. It will just be a bit more difficult and a bit more costly to install the 700R4 because of the driveshaft change required with the 200-4R.

If you can find one, correctly built for your engine's needs, the 200-4R is a simpler swap with the THM-400.

P.S. Either unit needs to be properly configured for your car, so the length is right for the Corvette.

riverracer au

700R4, as they are plentyfull down here, no one knows much about the 200-4r as it's not used in any of our local cars

TH400, was std in my 350 - 1972

yes, about 3", plus new output yoke and combo uni-joint

have a look at my fiddly bits thread.
https://www.corvetteforum.com/forums...ddly-bits.html

there will always be "other bits" see above link

mine was a late 92ish build from a local made car

i have a 3.08 rear as well

rosslato

This should help
https://www.corvetteforum.com/forums...ys-200-4r.html Post # 19.
I have a 73 400 turbo that i swapped in the 2004r. Did not have to change anything to the drive shaft except for the 350 Yoke., everything fit perfect. I used the stock Tranny mount w/no mods. Here is another thread on it w/great pics
https://www.corvetteforum.com/forums...-pictures.html
It's been 8 yrs since i did this mod, very happy w/it.

rkingce

I put a 700R4 in my vette, couldn't be happier. I had to get the drive shaft shorten ($100.00) and relocate the cross member. I have 3:08 and love it...... 70 mph at 1900 rpm. I can hear the radio and co pilot. The only issue is if im cruising at 70 and have to slow down to 55 the motor dogs alittle until I down shift manually. Other than that even with the 3:08's I have plenty of getty up and go. Oh ya 17 mpg with a 350ci / 350hp

doorgunner

From my reading, the 1989-92 700R4 held up much better.....and the external shift kit is a MUST to make the transmission shift in/out of "overdrive" correctly without "hunting" for lock-up/overdrive....most vendors offer the kits.

I put 200,000 miles on my 700R4 in my street truck 350 SBC with external shift kit.

Dean_Fuller

My frame is all together and powder coated...Really don't want to "relocate" cross member at this point. I want everything to be able to go back stock as easy as possible.

If I am understanding correctly the 200r4 requires NO cross member relocation or modification??

The 200r4 with a 350 trans yoke can reuse stock drive shaft?

rosslato

You can even reuse your inspection cover w/a few mods as i did.