Some will say the 700R4 is a weak transmission.
$2,400 plus a good torque converter, and mine is guaranteed to 700 horsepower. There is no way I will ever get to 700 horsepower with a small block...
Sounds like you will be under that with your big block.
4th gear overdrive, with lock up converter on the highway is awesome!
In my case switching from Turbo hydramatic 350 to 700 R4 I only had to slide the crossmember back to the next set of holes in the frame.
No modifications needed to the drive shaft. Shifter still works fine, I just can't push it all the way down into low one.
Dream come true for me! Super low first gear to get my 4000 pound Truck moving, and cruise at 85 miles per hour or no sweat. All day long!
Edit, I started with turbo 350 long tail in a Chevrolet pick up. If you have a short tail transmission , there is a few inches difference...

 

You might consider a Gear Vendor OD unit. It will bolt up to your 350 then shorten your drive shaft. Happy with the unit I have in a S10-V8 Blazer.

 

i looked at the gear vender but i just dont have the room with my frame configuration

 

Stand alone controllers for the 4l80e have become much better and common/cheaper then they were a mere 5 years ago.

With a few simple inputs you can have the thing shifting just as good as a aftermarket expensive 700r4.

The diffrence is that if you want to hit the strip changing when that 4l80e shifts can be as easy as pushing a button.
It will depend on how electronic your engine is and what features you want. But you can teach a old dog new tricks with a couple bolt on's(tps, etc) to make it a plug/play/tune weekend install.

 

You can consider a 200-4R. Lighter, smaller. They can be built quite strong.

 

You can consider a 2004R. Lighter, smaller. They can be built quite strong.

^^^THIS.

The 200-4R can be built to survive behind 9 second turbo Buick motors. It is the same overall length and same output shaft as your TH350 (assuming you have a short tail TH350). It does not require a computer, just a converter lockup signal (or build it with a non-lockup converter and pump). It has a normal mechanical speedo drive. It does require a TV cable (which is different from the kickdown cable on your TH350). The only issue is that the trans mount on the 200-4R is in the same place as the one on a TH400, not a TH350, so your trans crossmember will need to move back a couple of inches.

 

thanks for the comments never thought of the 200r4 i will have to do some more research
my set up is basic HEI with a holley the only electronics is my guage cluster dakota digital

 

The very early 200-4R cases are BOP only, but from about 1982-on they were all dual bolt pattern.

 

I run a 700R4 in my 41 Willys with a 3000 stall TQ, 3:90 gears and blown 562HP 350 sbc. (Yellow one at top of page.) It has a cheap lockup vacuum switch. It's been mostly drag raced for the last 8 years turning 11.5's. On the road it wants to run 80 MPH for it's sweet spot. Been about ten years but the TQ and tranny was like $1700.

 

200r4 Pro's and con's
Pros
Almost a direct bolt in
No electronics
"Light weight"
Can be built to handle the constant 500 ft/lbs that your 468 will put out.

Con's
TV cable
Shift feel
Even a "built" 200r4 has a limited life behind a big block that is abused on the weekends

4L80e Pro's and con's
Pro's
Built to handle 500ft/lbs in stock form
Fully adjustable electronic shifting allowing you control over the feel and shift points which means better street/strip tuning
Larger parts availability and support

Cons
Requires tunnel/cross member modification
Requires GPS or electronic speedometer adapter
Driveshaft
Generally more expensive conversion up front
Requires some type of controller
Requires you bolt on a couple things to a carburetor like a TPS etc.


The adjustability is something that most guys(including myself) love. You can have a 4l80e shift like a grandma transmission on the street with general driving. Then at the strip or just having fun you can change it into a different animal.
Want the thing to hold 1st for that 60ft. You can do that.
Want it to stay out of overdrive for that 1/8 mile. You can do that.
Want to not feel the thing shift around town. You can do that.
Want to keep the thing from shifting right after a power adder is turned on. You can do that.
Want to get a replacement out of a 3500 panel van in a junkyard. You can do that.


If you do not care about shift feel or tuning the thing more then the initial tune and just want overdrive then the 200r4 will work and bolt up.
If you see that 468 having higher compression and/or a future where tuning becomes important then the 4l80e may be a better choice.

 

4L80e Pro's and con's

You missed the part where he doesn't have room for a 4L80E. Also, he says this is a street car, not a drag car.

there is not alot of room around the TH350 (short tail shaft) the chassis does have an X frame so that is part of the limitation besides the exhaust/headers.

i find myself on the highway more often and the overdrive would be huge.

 

Torque is the bigger transmission killer than top end horsepower which is why the 200R4 could survive behind a turbo Buick. They can be built to live behind a street 454 just bring money to a well elected builder. The big attraction of the 200R4 is small steps between gear changes which is useful to the drag racer trying not to loose too much engine RPM on up shifts.

The 700R4 has a stronger case but has internal issues with standing up to big torque numbers in 4th. Much of that relates to excess heating of the oil. As with the 200R4 it can be built to tolerate big torque numbers. The 7004/4L60 has a wide ratio change between first and second that racers don’t like for the RPM drop but fo a heavy or underpowered vehicle and for in city stop then go is useful in getting moving and preserving some semblance of fuel economy in the city.

Both use a TV cable to modulate shift pressure, it is a bit funky to set up but works decently when set up correctly.

The 4L60E is an al electronic controlled version of the 700R4/4L60 it shares gear ratios, external dimensions and mechanical problems with them. The 4L80E is a derivative of the TH400, 3 speed. It only came computer controlled there is no equivalent step between mechanical and electronic controls as with the 700R4/4L60 to 4L60E. As you already know this is a big bodied gear box that is largely problem free but needs a controller as with the 4L60E for modulated shifts.

All of the 200R4 though the 4L60E can be built to withstand a 454 but require you make a decent financial investment on the front end.

Bogie

 

you all have given me alot of info and is truly appreciated this is strictly a street car never the strip, leaning towards the 200R4 as it is pretty much a very close direct replacement and with fitment being a big factor.
i am going to reach out to a couple shops that i have delt with in the past to see what they have and can do and of course dollars, unfortunately the guy that did my TH350 is no longer with us

 

Hi gear clutch pack likes to fail in a 700r4 and that stupid cable has to be adjusted just right. BUT Id go 700r4 with a 2200 stall or the 200r4. 2200 stall.