Freddy B

Rocket Riders,

I am in need of some information or assistance with a problem. I have a 71 Cutlass Supreme and I have desided to convert my column shifting convertible to a floor shifter with overdrive. I just have a few questions to get your take on things. I am looking for a 700r4 transmission to buy, has anyone rebuilt one, how hard was it? What all will I have to do to mount the floor shifter, I bought a console and shifter off eBay. Am I in over my head or can this be achived in my garage? Any help will be appreciated.

midrange

I just did this conversion (minus the 700r4) in the spring. Nothing to it in a garage, IF you have an Assembly manual. All of the measurements and floor plan dimple locations for mounting the console and shifter are in it, along with a lot of other information that could be very useful down the road for other 'hop-ups'.

You'll need the console mounts, any restro place online has them. I didn't have a console wiring harness in the car, but I made one up. Not factory, but serves the purpose. You'll also need the adapters for the shift linkage for the 700r4 to connect to the floor shift cable. Then there is the shifter/console indicator plate (P,R,N,oD,D,2,1) that adapts to an overdrive trans (also available online).
I left the stock column-shift steering column in, I just removed the shifter arm.

I'm also leaning towards an overdrive trans, a 700r4 is easier for me to get than the others, so that's the route I'm considering.

Freddy B

I do have an assembly manual I will take a look at the process. does the manual also show you how to remove the shift arm from the column, this sounds like a tricky task.

2blu442

Hi Freddy
If you use the 700r4 you'll also need an adapter plate to fit the Chevy bolt pattern to your Olds engine. Most people use the 200r4 as its already the BOP (Buick, Olds, Pontiac) bolt pattern. It also has different gear ratios specifically the first gear, some say it's more comfortable than the 700r4. If you have the time to do some reading try the search option or look through the transmission forum for old threads discussing this swap. I know this has been discussed before and several members here have done the swap. Here's a link to a company that sells individual parts or complete kits to make the swap your considering.

John

http://shiftworks.com/cutlas67-75.htm

midrange

Removing the shift arm is simple. Just drive out the pin that holds it in the column.

Some guys will grind down the **** that is left, or swap out the piece with a floor shift piece. I left mine intact since you can hardly see it.

If you are keeping the column shift column, make sure you leave the linkage hooked up that goes from the column (under the hood) down to the frame and then on to the trans. I disconnected mine, and since I didn't swap columns, I couldn't move the steering wheel due to the column lock not being disengaged when out of 'Park'. (I hope that made sense..... )

midrange

As far as the console mounts go, you can weld them in, or use short sheet metal screws to attach them to the floor pan. (just be sure that the screws won't hit anything underneath the trans/drive shaft tunnel)
I had my brother weld mine in, since I also converted to bucket seats and needed the seat mounts welded in.

HonestDave

I've done a few conversions over the years. I always prefer to buy a parts car and get every single piece I need from it, as well as the knowledge of where things go.

I realize that doesn't help as much, if you want a 4 speed automatic.

boese1978

[QUOTE=midrange;475840]Removing the shift arm is simple. Just drive out the pin that holds it in the column.

Some guys will grind down the **** that is left, or swap out the piece with a floor shift piece. I left mine intact since you can hardly see it.

I will be using my "left over ****/hump etc" as a mount for a tach......

midrange

[QUOTE=boese1978;475858]Good idea. Just keep in mind that if you do that, unless you have disabled the steering lock, neutral safety switch, and removed the linkages, the ****/hump will rotate down when you shift the car out of park. I didn't want to mess with the neutral safety switch or anything else, so I left mine alone.


If you get it to work without much headache, post the info. I'm not real comfortable messing with a steering column.

midrange

This pic here helped me the most as far as laying out the locations of the console mounts along with the Assembly Manual for the shifter.

rearbrackettoseatbeltholedim.jpg

Boldsmobile

That's my pic. More can be found here.

https://classicoldsmobile.com/forums...dual-gate.html

HonestDave

Don't forget all the little things like neutral starting switches, console wiring harness, reverse lights, etc.
You may need another neutral starting switch to also operate the reverse lights. If you just short the old switch, car will start in any gear. I'm thinking of mid-sixties cars, maybe 71 is different. Also I'm getting old. Brain could be a bit off....

Boldsmobile

Install on 71 would have those switches remain on the column.

cdrod

Freddy:
I've been researching the OD tranny swap for a '71 hardtop daily driver project I plan to start in a few years (I've got to finish my convertible project first). The 200r4 is practically a bolt in replacement for a TH350 (same length, BOP bolt pattern, etc). The gear spacing is more evenly spaced with the 200r4, the 700r4 has a steep 1st gear and a big gap between 1st & 2nd. Here are the ratios:
Tranny 1st 2nd 3rd OD rev
TH350 2.52 1.52 1.00 na 1.93
200r4 2.74 1.52 1.00 0.67 2.07
700r4 3.06 1.62 1.00 0.70 2.29

The 700r4 was designed for under-powered 4-bangers to get 'em off the line quick, but the drop in RPM going into 2nd is a kill-joy. You will need a throttle valve or 'TV' cable for the OD tranny's to maintain good pressure in the tranny or you will burn it up pretty quickly.

Hope this info is helpful.

midrange

Thanks for the info on the transmissions. I'll definitely go with a 200r4 due to the ease of installing (I have a TH350 now).
Is a TV cable easy to add? I know next to nothing about converting to an OD trans, but since I'm not doing it until next year, I have plenty of time to learn.

cdrod

I'm still collecting info on this swap myself, but I'll share what I do know. The TV cable connects to the carb linkage (like a throttle cable) and adjusts the internal trans pressure based on the throttle position; so low pressure at idle, high pressure at WOT.
One detail of the swap that I haven't yet figured out is how to connect to the Q-jet linkage and get the correct amount of "pull" on the cable. If the cable isn't fully extended at WOT, the trans pressure will be wrong. Best case, the shift points will be too early and soft; worst case, burn up the tranny. I'm told there are linkage kits to fit a Q-jet that allow you to adjust the TV "pull", but I haven't found any yet.