4 spd auto with lock up converter

[RGT]

I recently installed a Bow Tie Overdrive's 200R4 transmission in my '71 C10, really like it so far. I also took off the old headers and installed factory manifolds. I can actually hear the radio on the highway now. It's nice that the right holes were already in the frame for the crossmember to relocate to and that the driveshaft did not need to be changed. I do find that around town I have to keep the transmission in the 3 position instead of the D/OD position or it wants to shift into OD at too low a speed.

[James the III]

Originally Posted by RGT

I recently installed a Bow Tie Overdrive's 200R4 transmission in my '71 C10, really like it so far. I also took off the old headers and installed factory manifolds. I can actually hear the radio on the highway now. It's nice that the right holes were already in the frame for the crossmember to relocate to and that the driveshaft did not need to be changed. I do find that around town I have to keep the transmission in the 3 position instead of the D/OD position or it wants to shift into OD at too low a speed.

re check the tv cable..
and remember they where for cars to get better mpg.. so getting into high gear early helped.. might have to rework it to go into o/d at a higher speed..

[RGT]

Thanks, I went through their setup procedure for the tv cable, I still need to remove the gauge. I will check with them, unless someone knows how, about trying to get a later high gear shift, for now it is fine as I am either around town or on the highway for some stretch so I am not shifting back and forth..

[LongBox]

Interesting. I would like to know what change in gas mileage you get from this swap. Also, it seems that this can be done with either the 200R4, or the 700R4. What are the differences between these transmissions, and is the 700R4 as easy a swap as the 200R4?

[RGT]

I got the impression when I was looking that the 700r4 might be better for higher hp applications but when I talked to Bow Tie they thought the 200 was fine for my stock application. For the couple of gas tanks I have run through I don't see a noticeable improvement in the mileage, just a lot nicer to drive. It is also winter and my qjet seems to leak down pretty quick between trips and is also not set up very well for this tighter driveline, so there may be some gains to be had by getting the carb tight and tuned better for this application. Other than rebuilding these Qjets I don't know much about tuning them. Anyone have any good advice on what would be a good carb to swap in? or am I better just trying to epoxy in the internal plugs on this qjet and figuring out how to dial it in better. I am currently running it with a manual choke.

[HO455]

The in and out of forth gear around town is a killer for the GM 4 speed autos. I went round and round with my ex about leaving her Camaro in OD around town. She swore the salesman told her it was best. She lost her first tranny at 68k the second one 11000 miles later, and my Blazer is at 177k and going strong. I stay out of OD unless I'm on the highway for more than couple miles. If I don't it will shift into forth about 38 miles per hour.

[darrellyates]

It's my understanding that the 200R4 is based on a turbo 350, and that the 700R4 is based on the turbo 400.

I switched out a turbo 350 for the 200R4 in a Ford pickup street rod I had, and loved it. Mine had the electronic lockup converter, and was wired direct so that it went in nearly immediately in both 3rd and 4th unless you were really standing on the gas (cable was adjusted properly too...).

I also drove it around town in 3rd gear, and bumped it into and out of overdrive when I got on the highway. It returned good gas mileage (over 20mpg, great for a carb. engine) and I never had an issue with it.

For me, the bonus was the easy conversion from the turbo 350, as the 200R4 is the exact same length overall, and that way I didn't have to modify the driveshaft or any difficult parts. (It was a tight fit under the 1935 Ford truck, but so was the turbo 350.) Even the yoke is identical to a turbo 350 trans.

I'm a fan of the 200R4. It actually has a lower first gear, and taller final drive than the 700R4. And, I didn't make enough horsepower or have a heavy enough vehicle for it to matter.

I would use a 200R4 again without a second thought. I think they are extremely good transmissions.

[Project1970]

You're thinking of the 4L80E, that one was based on the TH400. The 700R4 was a new design.

[jessemthompson]

The 700R4 actually has a steeper first gear. 3.06 vs a 2.74

[RGT]

I did install a switch so I can lock up the converter while running around in 3rd

[James the III]

Originally Posted by LongBox

Interesting. I would like to know what change in gas mileage you get from this swap. Also, it seems that this can be done with either the 200R4, or the 700R4. What are the differences between these transmissions, and is the 700R4 as easy a swap as the 200R4?

The 2004r fits where a th350 was..
the 7004r does not, you need crossmember mods and cut drive shaft.
the gear splits are different the 7004r 1 to 2 is huge.. but it was for mpg and to get the car/truck moving without tons of pedal movement..

no 7004r with bells for o/p/b/ only chevy..

The 7004r lived on as that 1 to 2 gear drop and low 1st gear was needed to get heavy trucks going and still get good mpg..

They both take the cash to build into strong transmissions..
2004r died with the g body and square/boxy b body's the 7004r didn't so parts can be an issue..
the 4l80e /4l85e is a th400 with o/d added.. and better than both..

the 2004r and 7004r got a bad rap, but neither was designed for the power people put threw them.. o.e.m. v8's made 200 h/p TOPS most in the 165-180 range . not made for 300hp

[67ChevyRedneck]

It's common to have to leave a 700R in 3rd when your driving under 45 mph. Under light throttle they'll shift in OD around 40mph and these trucks are just heavy old aerodynamic bricks. I had an 86 Z28 that had a 305/700R (LOL, right? - it was S L O W!) and it did the same thing, wanted to shift into OD at 40, which was just too early. In my C10 I have a lokar floor shift so it's easy for me to bump it back and forth.

My 700R has been in my truck for +/-11 years and probably 50-60K miles. Still shifts like it did when I installed it. Fuel mileage didn't really change around town, still get 11-12mpg. Back road cruising and highway driving gets 15-16mpg. I did it more for the rpm noise drop than the mileage as I put 3-5K miles per year on the truck.

[tdangle]

RGT, What gearing do you have in the back? Does the lockup only occur when you flip a switch or is automatic unless you want to lock up in 3rd? I'm considering the same thing in my 70 C20. It has 4.10's so shifting into 4th at 40 may not be too bad.