Transmission change from 350 to ?
Thread Starter
Cruising
Joined: Jan 2004
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From: Sikeston mo
Transmission change from 350 to ?
I have a 1979 vette and has the 350 auto trans. I am thinking about changing out to a 700r4. I had read about a 200r. but not sure. just wondering if anybody else has done this change out and what kind of problems if any I will run into. I think I will have to modify the driveshaft with the 700r4, but not sure of any more things I will run in to. Thanks for any info. hile62
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From: Severna Park Md
Re: Transmission change from 350 to ? (hile62)
Just for what its worth. I have heard of several people on here mentioning failures in the 700 transmissions. Havnt heard of any with the 200. I think the 200 is better. Whats making you lean towards the 700?
Le Mans Master
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From: absecon nj
Re: Transmission change from 350 to ? (427V8)
I replaced mine with a 700r4,i made a transmission crossmember and cut the driveshaft to fit.I also file the shifter plate some so i can get first gear with it.I agree about the low first gear its a blast with 3.70 gears.Some people prefer the 200 some like the 700.I see the abuse the 700's get with the police cars i work on,ive seen some last 100,000 and some 10,000 miles.
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From: Waterford Mi
Re: Transmission change from 350 to ? (patsnitrovette)
The 200 was just about as close to a direct drop-in as you can get. I do recommend changing the detent plate on the shifter rather than trying to mod the existing one because it is possible to end up with the trans to be in two gears at the same time if it isn't correct. Not to say that it can't work by moding but chnaging it out is very simple so why not do it.
More info on my web page.
More info on my web page.
Le Mans Master
Joined: Mar 2002
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From: Coming home from Luckenbach Texas
Re: Transmission change from 350 to ? (hile62)
For a '79, I'd recommend a properly-built 200. It's a direct drop-in replacement for the TH350. It uses the stock crossmember, and the driveshaft does not need to be cut. Also, the gear spacing is similar to that of the 350, plus that *extra* 4th gear you dearly crave. The 700 has a really low "granny" 1st gear, which is great for lower-ratio rear ends, like 3.08 and below. But because the late-70s C3s had mostly 3.55 or 3.70 rear gears, the 200 is better suited to the task.
And we're still waiting to hear of a failed 200-4R on the forum. We've discussed many blown 700's, but none of us 200 users have had a problem. And in case you're wondering, the 200-4R was originally used in the Buick Grand National and Monte Carlo SS, among others.
And we're still waiting to hear of a failed 200-4R on the forum. We've discussed many blown 700's, but none of us 200 users have had a problem. And in case you're wondering, the 200-4R was originally used in the Buick Grand National and Monte Carlo SS, among others.
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Re: Transmission change from 350 to ? (page62)
i have had no problems with my 700 r-4- i got it behind a 383 stroker and have no complaints- the car really comes outta the hole with the 373 gears and on the highway you gotta love 17 mpg- i just changed the one in my astrovan---i got 300,000 outta the first one- all i can say is you who are having problems must have a build issue- you cant ask for more than 300,000 miles outta a tranny
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Thread Starter
Cruising
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From: Sikeston mo
Re: Transmission change from 350 to ? (Jvette73)
I was not aware of a 200, not much on trans. I have had a couple cars(not vettes) with the 700 in them, that was why i was asking about the 700 thanks for your input
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Thread Starter
Cruising
Joined: Jan 2004
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From: Sikeston mo
Re: Transmission change from 350 to ? (redwingvette)
Just wondering is the detent plate in side of trans, or are you talking about the dentent cable also. Or are we talking about the dentent plate being at the gearshift in car.
Le Mans Master
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From: I blame my Dyslexia MD
Re: Transmission change from 350 to ? (hile62)
Alot of the problems wit hthe 700R on here has to do with the 3rd gear. That problem is linked to some peice that must me removed or changed or somehting like that when you buy it new. I odnt rememebr what the peice is but its btwn 3rd and 4th gear. I was tlaking to a rtanny guy at carlise about it and thats what he told me. Its kind of like how you have to remove the little plastic peice form the magnetic suspension on the C5 but not all the dealerships know to so alot of peopl get realy bumpy cars :yesnod:
Thsi is jus twhat he told me and my memory doesnt serve me too well on the subject, its just most of the do it at home intallers skip over this simple step because they dont knwo of it.
MAtt
Thsi is jus twhat he told me and my memory doesnt serve me too well on the subject, its just most of the do it at home intallers skip over this simple step because they dont knwo of it.
MAtt
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From: Waterford Mi
Re: Transmission change from 350 to ? (hile62)
The detent plate is the plate welded to the shifter with the slots/grooves in it that places the shifter in the proper position for the trans. PRNO321. The difference between the one you have and the one for a 200r4 or 700r4 is the location of PRNO and the placement of 321. The total distance from P-1 is the same. The safety neutral switch will need to be adjusted which depends on what year you have.
Le Mans Master
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From: Lebanon Township New Jersey
Re: Transmission change from 350 to ? (redwingvette)
If someone can clarify one thing for me I would appreciate it. Does the 200 4R trans use a different converter than the TH350?
Le Mans Master
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From: absecon nj
Re: Transmission change from 350 to ? (BKbroiler)
The 200 and 700 use a different converter compared to the 350/400's,they use a lock up converter.You can get a non lock up also for the 200's and 700's.
Race Director
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From: San Francisco CA
St. Jude Donor '07
Re: Transmission change from 350 to ? (hile62)
From what I understand, the only weak point on the 700 is the 3-4 clutch pack. I've heard it'll fail if you don't drive properly, like if it shifts too often. Someone was saying 4th is only for sustained freeway speeds and cruising around town you should leave it in D3. I don't know if this is right or not, but it's a good starting point for research. Good luck!
Le Mans Master
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From: Coming home from Luckenbach Texas
Re: Transmission change from 350 to ? (Buffalo Dude)
This really shouldn't be a discussion of the relative strengths and weaknesses of the two transmissions, and I'm sorry if I helped create that impression. The 700 is the best fit for the earlier C3's originally equipped with TH400 trannys and lower rear gears like the 3.08.
The 200-4R is a good fit for the later-model C3's because it's a direct bolt-in replacement for the TH350 -- no driveshaft cutting and no replacing the crossmember. And the 200-4R's 1st gear ratio is more similar to the TH350. Finally, becuase most of the 78-79 C3s had 3.55 (or 3.70) rear gears, this 1st gear ratio works better under normal driving conditions.
The 200-4R is a good fit for the later-model C3's because it's a direct bolt-in replacement for the TH350 -- no driveshaft cutting and no replacing the crossmember. And the 200-4R's 1st gear ratio is more similar to the TH350. Finally, becuase most of the 78-79 C3s had 3.55 (or 3.70) rear gears, this 1st gear ratio works better under normal driving conditions.