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Discussion Starter · #1 ·
I am looking for a 65 SS and I am so spoiled by the overdrive on my Tremec TKO that I want to put an overdrive in my 65 for cruising to replace the Powerglide.

I have heard many stories and I know the answer is "it depends" but, Is there any easy install for an overdrive in a 65? I was thinking 700R4, but I have heard they need to be beefed up and require a computer???????

Any feedback is appreciated. We are talking less than 350 HP small block, no racing.

Thanks
Chuck
 

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For your HP level, the TH700 will live. You need a correctly set up TV cable and the converter locked up in 4th.

The 700 does not require a computer. It will require you to shorten the drive shaft.

The TH200 will require the TV, the lock up, but will not need a shorter drive shaft.

Consider the 700 as a wide ratio and the 200 as a short ratio, with a similar OD.
 

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Discussion Starter · #3 ·
Thanks Zeke,
What do you mean by wide ratio and short ratio? Do you mean the step from gear to gear? I assume that 3rd is 1:1 and that 4th is like a .7 OD or something like that. I really want the smoothest shift possible, mostly road use.

I will have the look up the 200 and 700. I'm not very auto tranny literate. I am only familiar with the TH350 and the TH400.

Thanks again Zeke.
Chuck
 

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Yeah, the step from gear to gear. You are right on 3rd and 4th. First is lower in a 700 than in a 200.
 

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I've got a 700R4 behind a ZZ4 pushing 300 hp at the wheels. The tranny is a Street Fighter from TCI. No problem with tunnel clearance using a BowTie Overdrives crossmember. Not a difficult install. Many others have done the same setup. I'm using ShiftWorks conversion kit for the SS console shifter. The Streetfighter shifts hard in 1st and 2nd, my opinion, so I made the shifting a bit softer (I don't race).
 

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Discussion Starter · #6 ·
OK guys, thanks. I did a bunch of searches on the subject (which I recommend to everyone, haha) and I have a couple questions.

First the 700R4 and the TH700 names seem to be interchangable as with the 200. Is that correct????


Secondly, what's the difference between a "lock up" 4th gear and the standard 4th gear?


Wait, one more: Right now I get about 2000 RPM in 5th gear in my 67 with 3.73:1 gears. I like it a lot. What gears do I gave to run in the 65 with the 700R4 to do the same?

Thanks everybody. I know about a lot of Chevelle stuff but I'm a dummy on trannys (except my TKO-600).

Chuck
 

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Some people (I'm one) will use TH700, 700, 700R4 interchangeably. They all mean the same thing - the Turbo Hydramatic 700 R4. Similar with TH200, 300, 2004R. But you have to take this one in context because a TH200 and a TH2004R are different. The former is a 3 speed common in small cars in the 70's and the later is a modern 4 speed OD derivative. But the 700R4 and the 2004R are different from each other.

4th gear is 4th gear. "Lock up" is referring to the clutch in the torque converter. Both the 700R4 and the 2004R really need to have the torque converter locked up when in 4th gear.

I don't know your 5th gear ratio in your TKO, but if you do, you can do the math yourself. It's a simple proportion between the rear gear with your five speed OD ratio (both are known) and the .7 OD in a 700 and the unknown rear gear ratio you want to determine.
 

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If you start talking to people about a 200, there is a bit of difference so make sure you are talking about a 200r4.

A 700 has .7 overdrive and the 200r4 has a .67.

With the 200r4, 3:73 and a 28" tire you should be at or just below the 2000 rpm range. Maybe slightly higher with the 700.

Here is the math I found for Overdrive trannys
MPH X Rearend gear ratio x 336 / tire diameter = rpm x O.D. Ratio
 

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Discussion Starter · #9 ·
OK, thanks. The TKO is a .67 so the .7 is close enough to spit at. I think I will go with the 3.73 since I am actually a little below 2K at 65 in the 67 with the TKO-600. I think I will go with the 700R4. I like the first gear.

Thanks for the help guys. Stop by the Electrical Forum any time. I can actually answers questions over there. I appreciate the help.

Chuck
 

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If you can't feel it by counting gear changes , tune your radio to AM off station, and you should be able to hear buzz from engine interference, then you can hear gear changes.Count as it happens...1-2 ; 2-3;3-4; 4 to lockup .Not foolproof tho , a 700 can be set up to go to overdrive when the 3-4 gear change happens,This will usually lug down engine at low speed.
 

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The torque converter has a lock up clutch in it. The circuit to control it is in the trans pan. You can buy a kit for this or fab your own.
 

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I tried listening to the gear changes and I don't hear it do the extra "shift" into lock up mode. Is there a cable coming off the trans. that I can check to see if it's connected?
What happens if it doesn't lock up? Is the locking up to get rid of slip between engine and trans?
 
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