dan402 Posted January 8, 2023 Share Posted January 8, 2023 Happy New Year ! I am looking for an overdrive trans for my 72. I had planned on changing over to a 4 speed manual , but due to a recent left knee injury am reconsidering. I have the pedal kit and everything to do the 4 speed swap which i purchased from a group member when he upgraded to a 5 speed. Quote Link to comment Share on other sites More sharing options...
420ponies Posted January 8, 2023 Share Posted January 8, 2023 (edited) Long time since we've seen you Dan, welcome back! Can't help with the overdrive but, I know a friend that could build you one in north central PA. He built my 2004R and it's held up rather nicely. Let me know(PM me) what you have on the 4 Spd stuff, may interested. I. Just hope it wasn't a skiing accident ( the knee injury). Edited January 8, 2023 by 420ponies Spellcheck Quote Link to comment Share on other sites More sharing options...
Scott S. Posted January 9, 2023 Share Posted January 9, 2023 I've also done the 200r4 swap.... Liked it better than the 700r4 version. The 200r4 is pretty much a bolt in, whereas the 700r4 will require several modifications to the drive train. I found it at a local Pick n Pull, then took it to a guy who specialized in rebuilding hi pro transmissions. Been working fine for the last couple years now. 3 Quote Link to comment Share on other sites More sharing options...
Brew Posted January 9, 2023 Share Posted January 9, 2023 I switched to 700r4 & love it. The overdrive is awesome. First I heard of 200r4. Live & learn 😎 1 Quote Link to comment Share on other sites More sharing options...
420ponies Posted January 10, 2023 Share Posted January 10, 2023 Big to do for the Buick Gran National (GSX's) '85-'87 .My case is from one.All new internals, more line pressure, little upgrades, and hard shift only when on the throttle. Got around 18 mpg with the 420 hp sbc, (3:42) geared 10 bolt. 1 Quote Link to comment Share on other sites More sharing options...
McCall72 Posted January 10, 2023 Share Posted January 10, 2023 I have a 200r4 in my 72 from a 1985 Monte Carlo SS married up to a 12 bolt posi with 3:31 gears. Cruises st 1900 - 2000 rpms at 70 mph. Wonderful transmission. 2 Quote Link to comment Share on other sites More sharing options...
cbolt Posted January 10, 2023 Share Posted January 10, 2023 I have a 200r4 in my '72 married to a 10 bolt 3.73 locker. I love it as well but in hindsight I would have gone with 3.31's or 3.55's 1 Quote Link to comment Share on other sites More sharing options...
Scott S. Posted January 10, 2023 Share Posted January 10, 2023 7 hours ago, cbolt said: I have a 200r4 in my '72 married to a 10 bolt 3.73 locker. I love it as well but in hindsight I would have gone with 3.31's or 3.55's After my swap, I still had the 2.73 gears in Montelishi..... Crusing the highway at 1500 rpm's was nice, but stoplight to stoplight sucked. Went with the 3.31 12 bolt and it's been perfect. She'll even chirp the tires in second gear. 1 Quote Link to comment Share on other sites More sharing options...
Scott S. Posted January 10, 2023 Share Posted January 10, 2023 20 hours ago, 420ponies said: Big to do for the Buick Gran National (GSX's) '85-'87 .My case is from one.All new internals, more line pressure, little upgrades, and hard shift only when on the throttle. Got around 18 mpg with the 420 hp sbc, (3:42) geared 10 bolt. Had an '86 T-Type.... That's where I fell in love with the 200r4. The one I had rebuilt for Montelishi is from an '84 Cadillac Fleetwood, but I got the builder to set it up to the GN specs and heavy internals. There's a difference pre/post '85 transmissions. The newer versions use a different selenoid internally. 1 Quote Link to comment Share on other sites More sharing options...
Scott S. Posted January 10, 2023 Share Posted January 10, 2023 22 hours ago, Brew said: I switched to 700r4 & love it. The overdrive is awesome. First I heard of 200r4. Live & learn 😎 700's are the prefer swap. Heavier duty and more commonly available. They also all come with the "BOP" bolt pattern. 200's are getting hard to find because they were such an easy install into "G" bodies. Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted January 10, 2023 Share Posted January 10, 2023 19 minutes ago, Scott S. said: 700's are the prefer swap. Heavier duty and more commonly available. They also all come with the "BOP" bolt pattern. 200's are getting hard to find because they were such an easy install into "G" bodies. I'm sorry, you have that backwards. The 200r4 has the "BOP" bolt pattern. The 700r4 ONLY came in a Chevy bolt pattern. The 200r4 has a gear split similar to the th350 while the 700r4 has a 3.06 first gear to a way higher 2nd gear. The gear split in the 700r4, when looked at is not more favorable than the 200r4 unless you are using a 3.00 or higher rear ratio where the 700s lower first gear ratio will help move the car from a stop a little easier. 1 Quote Link to comment Share on other sites More sharing options...
Scott S. Posted January 10, 2023 Share Posted January 10, 2023 Yeah, sorry about that.... The 700 was more of a "universal" Chev transmission, which included their use in trucks. Another bonus to the 200r4's is the higher overdrive gear. They don't dig as deep off the line, but are nicer on the top end. 1 Quote Link to comment Share on other sites More sharing options...
Scott S. Posted January 10, 2023 Share Posted January 10, 2023 2 minutes ago, Scott S. said: Yeah, sorry about that.... The 700 was more of a "universal" Chev transmission, which included their use in trucks. Another bonus to the 200r4's is the higher overdrive gear. They don't dig as deep off the line, but are nicer on the top end. I recall a post on here where someone was setting up a TH425 for drag racing because it has a really deep first gear and a tailshaft brake. Wonder how that worked out. Quote Link to comment Share on other sites More sharing options...
Whons Posted January 13, 2023 Share Posted January 13, 2023 I have a 700R4 transmission in my 70 Monte Carlo. they will bolt up to a SBC. You will have to cut and weld the drive shaft to make it shorter, then have it balanced. Depending on your carb. you will have to get a special linkage arm that attaches to the throttle linkage arm. all carbs use a different arm. The shifting is controlled by a Throttle Valve cable. The adjustment of this cable is very critical. It shifts by MPH. From 1st to 2nd at 15 -20 mph 2nd to3rd at 25 to 30 mph and 40 to 45 mph which is overdrive. This may very a little, but has to be close. Remember I'm the guy that hired the Lemon Squad and lied about doing a road test. My transmission was good but not set up properly. I had to take it in to a special shop that new how to do all this. They ended up putting a new shift kit and put different springs and weights in the valve body.The guy who did this owns a 70 Monte. This cost me about $800. Now its great. I get 11 mpg city and 18 mpg highway. pretty good for an engine with 420 HP. It chirps the tires from 1st to 2nd. I did a lot of research on this. 2 Quote Link to comment Share on other sites More sharing options...
Montemedic Posted January 13, 2023 Share Posted January 13, 2023 Dan, Whichever way decide on will be good. A bit of physical therapy while rowing thru the gears isn’t a bad thing for your knee either. Quote Link to comment Share on other sites More sharing options...
Jason72 Posted January 13, 2023 Share Posted January 13, 2023 The cable on the 700 is a throttle valve cable. It controls line pressures at throttle position. That is why if not set properly you can smoke the trans in a hurry If having a 700 built, install a constant pressure valve body. It transforms the tv cable to a kick down and the pressure is controlled more like a th400/350. the shift points are controlled by the governor. Changing the springs and weights changes shift points Quote Link to comment Share on other sites More sharing options...
Scott S. Posted January 13, 2023 Share Posted January 13, 2023 It's a tricky cable to set.... Wound up getting my transmission rebuilder to do it (he'd set up a few already). Not to forget the ignition power to the overdrive either. Missing that will roast the trans in a hurry too... Quote Link to comment Share on other sites More sharing options...
Whons Posted January 13, 2023 Share Posted January 13, 2023 I'm sure mine is all hooked up properly since I had a transmission guy work on it. It goes into overdrive properly. I've put 1000 miles on it since the shift kit and all the springs and weights were adjusted in the valve body. 1 Quote Link to comment Share on other sites More sharing options...
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