Ask Away! with Jeff Smith: Is a GM 200-4R Automatic a Good Choice for a Mostly Stock 1968 Camaro? What Transmission Would You Recommend?


I have a really nice 1967 Camaro that my sister bought from the first owner way back in 1979. It’s a California car with a matching-numbers SS350 engine with a Powerglide. The engine and suspension have both been fully rebuilt stock except for a slight drop in compression and a very mild cam upgrade. The engine makes around 300 horsepower. It’s mainly a cruiser with factory A/C and it even retains the California smog pump. I’d like to leave it all as factory as possible, even using the tweaked OE shifter.

I’m thinking seriously about doing a 200-4R transmission swap, mostly so I can drive the car more comfortably on the highway. It’s pretty busy with the ‘Glide and stock 3.08:1 rear gearing. Doing some research, I came upon a story you wrote about converting to a 200-4R transmission and converting the shifter. Is this still a good conversion?

N.M.

In the past, I was a big 200-4R fan compared to the 700-R4 for several reasons. More recently I’ve changed my thoughts based on two things:

1. Availability of these transmissions is becoming very limited. These transmissions were mainly used in Pontiacs and some Oldsmobiles in the late 1980’s which makes these transmissions roughly 30-plus years old. Rebuildable transmission cores are becoming difficult to find.

2. The TV cable is very difficult to set correctly. It can be accomplished with a quality set of brackets. Of course, this same issue applies to the 700-R4 as well. 

The 200-4R Transmission Swap

If you already have a 200-4R to rebuild that is in good shape, then yes I would go with it. My experience with the 200-4R was as a result of the story that you mentioned. I worked with Art Carr, who now runs California Performance Transmissions in Southern California. I still have that transmission although it is no longer in my ’66 Chevelle—we went back to a TH400 built by my good friend John Kilgore to test his SuperLite 400 transmission.

Over time, we discovered that there was some minor issues with our 200-4R. We could never achieve the wide-open-throttle (WOT) up-shift rpm that I wanted, so I always had to manually shift the trans. The 200-4R, like the 700-R4, sets WOT shift points with the governor springs and weights, and these are less than accurate in many cases. My 200-4R would not automatically up-shift at WOT any higher than about 5,500 rpm so I had to manually shift it when we ran it at the track. Otherwise it was a fantastic transmission. It’s possible that we did something wrong with governor because it should work better than what we could do with it. I also highly recommend a lockup converter for whatever overdrive trans you decide.

With either the 200-4R or 700-R4, it would be a good idea to change to a deeper rear gear since the overdrive for a 200-4R is a 0.67:1—which is an aggressive 33 percent! Just multiplying numbers, with a 3.08:1 rear gear, shifting into overdrive will change the effective rear gear ratio to 2.06:1 This is a really tall gear ratio that at 70 mph with a 26-inch tall rear tire will bog the engine down to 1,864 rpm assuming a lockup converter. You’d really rather be somewhere around 2,200 to 2,300 rpm at 70 mph. A 700-R4 or 4L60E is roughly the same overdrive ratio at 0.70:1. 

Alternative Transmission Choices to the 200-4R

Instead of the 200-4R, lately I’ve be leaning more toward the 4L60E – 4L65E – 4L70E family of transmissions.

All of those are electronic transmissions. With the correct controller, these transmissions will shift at part throttle and WOT at exactly where you set them with no need to fumble with a TV cable or mess with tuning the governor springs. However, this will require a separate electronic controller. This tends to add to the total cost of the transmission but in my opinion, this is well worth the investment.

When converting an early Camaro to a four-speed automatic, Shiftworks makes a kit to convert using either a completely new shifter or you can convert the original shifter to control all four gears. Both come with a new plastic indicator that indicates overdrive. (Image/Summit Racing)

One item that may affect you decision is that the 200-4R will be almost guaranteed to fit under your stock floorpan with no modifications. A 700-R4 or 4L60E will, on the other hand, likely require some minor floor pan mods to clear the transmission’s servo housing on the passenger side. These will only require some minor hammering of the floor and not any serious cutting or welding but it’s worth mentioning mainly because you are starting with such a pristine car.

The GM 4L60E case is roughly the same size as the TH-350 or 200-4R but does position a servo housing on the passenger side that may offer some floor interference issues (Image/Jeff Smith)

The 200-4R’s overall length is only slightly longer than a TH350 so often the driveshaft will not need to be changed from the Powerglide unit but the crossmember will need to either be modified or a custom crossmember can be used because the 200-4R places the rear trans mount farther back compared to a TH350 or Powerglide.

We’ve listed a crossmember and shifter conversion parts in a Parts List at the bottom of this story.

There are essentially two different 4L60E GM automatics—one for the original SBC style bellhousing and one with a different converter depth for LS style engines. You will want the one for the traditional SBC style.

I did some quick comparison shopping with a large aftermarket performance automatic company and a complete 200-4R kit (except for a crossmember or driveshaft) was roughly about $1,000 less than a comparable kit for a 4L60E version. The majority of that cost was in the price of the separate transmission controller. This is a big hit in terms of cost—roughly about a third more expensive than the 200-4R transmission. So if this additional cost is prohibitive, then the 200-4R or a 700-R4 is a good way to go. 

1967 Camaro Swap Parts List  



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