[Jim's69Ragtop]

Hi -

My 69 (mild 350 ci) currently has a column shifted TH350 with a leak that I haven't been able to resolve. I beginning to believe I have a hole or crack in the case based on the leak coming from the top side above the governor.

Just got a quote from Bowtie Overdrives for ~$2200 for their level 2 700R4 kit (all of the necessary pieces to swap with the TH350). That was a bit higher than expected, but there's more. Because my rear end gears are 2.73, they're saying I can't really run this tranny without going to something like a 3.73. To do that swap, I'm looking at another $1300 or so.

So my dilemma is do I sink ~$4K for this complete swap or go for another TH350 for probably $1K? I guess what I'm looking for is will the "Oh wow!" factor be so dramatic with this new setup and worth an additional $3K?

I realize in the end this is a decision I need to make, but looking for feedback on others who may have made the same change.

Thanks in advance -

jim

 

[Robinls5]

Here is what I did. Went to Stans Transmission in McKeesport. My 700R4 is out of a mid eightys 454 Suburban, & Rebuilt with a stock converter, sitting on the shelf in a plastic bag. I had a 700 already in my 71. It was working well BUT it was from a 305 and I new it would not live to long.
Total cost installed was $950.00 exchange.
NOTE: To install a 700R in a 70-72 Chevelle, This is the good news.
1--Your stock 350 lines on the tranny will bolt directly to the 700
2--Your stock colum shift linkage will work no alterations.
3-- Move your crossmember back and drill TWO holes--one hole on each side lines up ,,So just drill one new hole on either side.
4--Shorten the 3/8" dia. Emg. brake cable guide on the Pass side, The same amount you moved the crossmember back.
5--The items you need for the TV cable ,,Chances are you have enough " STUFF " in your garage to make these items.
When you get that far. E-Mail or call me I have all the specs. and measurements. My tranny has been in my 70 for 9 years or 42000 miles. In front of my 700 is a 468 B.B. Also the mid eightys 700s have a cable drive speedo, Just screw your cable to the 700.
Cut the D-Shaft around 2'= $50/60.00.
The bottom line is a 700R4 is the same as a T-350, But it has an O.D. unit attached.
Bob

 

[Verle]

Unless you are planning to change the mild 350 for a built big block you don't need to spend that kind of money for a 700R4.

The overdrive with a 2.73 will be pretty tall.
With 26" tires, 2000 RPM will be about 75 MPH.
That should work with a mild cam and small carburetor (Quadrajet?)

 

[zeke67]

IMO you've got to put serious money in a 700 to make it live. I've done the junkyard swap TH350 and it lived. The junkyard 700 swap did not. It was good for a core and all the bits and pieces (like TV cable), so it paid for itself. Then I did a budget build 700. It didn't last either. Best thing that came from it was I upgraded to a 93 Camaro case. Last one has been a performance build and so far so good. It was local and a little less than the price you've got, but I had a good core to start with.

The rear gear swap is a must with the 700. But other than it hits our check book at the same time as the tranny, remember that even your TH350 would really wake up in front of a 3.73 rear.

 

[Alan F]

What's your plan for the car? It sounds like you ought to just have another 350 built UNLESS, you have a big plan to upgrade the performance. A smallblock auto 2.73 car is a very comfortable and economical cruiser.

 

[Jim's69Ragtop]

Thanks for everyone's response. The consensus appears to be stay with the TH350 under the current setup. At some point (phase 2) I may address performance with another engine, etc. but at this point I'm trying to get it mechanically sound and continue to address the body.

Anyone have experience with TCI (TH350) StreetFighter 311000? Summit sells it for just over $1k - about $100 less than TCI.

Other recommended vendors?

Thanks again -

jim

 

[Dmax]

I have been running a 700r4 with 3.07 gears and its totally fine. Very economical on the highway. I am however in the process of getting 4.10s under there to make it rip instead of economical. I had a local guy build and install the 700r4 for $2500. He rebuilt it to work well in the chevelle with a high stall torque converter and other goodies.

 

[Andy's Auto Repair]

Anyone have experience with TCI (TH350) StreetFighter 311000? Summit sells it for just over $1k - about $100 less than TCI.


Thanks again -

jim

Funny you should ask. I have the StreetFighter behind the mild 496 in my 71 Monte. I put just over 14,000 miles, mostly beating it on the way to the track, at the track, and home from the track. The pic is 4300 pounds, a 3500 convertor, 3.73s on Drag Radials. The car runs [email protected] on motor, and I have been known to beat it with a 150 from time to time.

So yeah, that little 350 that could has done a pretty good job for the last 4 years. I have serviced it once as I ran the car hot when an alternator froze up on me breaking the belt. But never an issue.

I personally think that particular tranny is just a freak. Never heard of any 350 out the crate that has done what this one has endured.

 

[Bullcrappy]

if changing to OD why not the 200-4r ?? better ratio and can be built to handle 700+ hp

keep drive shaft... just move cross memeber...

 

[Jim's69Ragtop]

Yeah, I have that same question out to Bowtie. They went right for the 700 - not sure why. My understanding is the 200 requires less mods - mainly no need to shorten drive shaft and the 1-2 ratio isn't spread as much as on the 700.

Main concern with either is the 2.73 rear ratio. Ultimately I want to change to something in the mid to upper 3's, but can I get by for now?? Can I simply run in D vs. OD if I'm lugging the engine too much?

jim

 

[pizzi-man]

Running the 200r4 with 3.08 rear gears. Shifts like a regular trans except for the fact that I don't lock the converter unless I'm cruising at 70.

 

[66 chevelle 496BBC]

fix the leak and be happy! then later get a posi 3.73. then you will need a 200-4r. but get a good one. i blew one from a monte carlo SS with my 496 in 3 short rides (beatings). i bought a custom built one fron CK performance and all is well. you need the geomerty corrector for you carb with the cable set properly. not hard to do at all.

Jim

 

[sparks]

I had a local trans shop (AAMCO) build a TH350 to back up a 327 with appx. 325 HP. Had all heavy duty clutches and shift kit put in it. Used TH400 converter for it's slightly higher stall speed. This trans kicked ass. Stock 3:08 rear. Trans "chirped" rear tires shifting into 2nd at appx. 4000 rpm. Total cost $549 including TV cable and flex plate. Now this was 10 years ago, so I don't know what it would cost in todays dollars. But I would check around before plunking a grand plus shipping. I also liked the fact that I bought local. If and problems were to arise, I could handle it face to face.