How's a th200 4R going in a V6 231 3.8L Chevy?

J. Gregorio

Not-quite-so-new-guy
Dec 4, 2020
18
3
Hi guys! I have a 1983 Chevy Malibu Classic 4 door, equipped with a 3.8L 231 V6 engine and I am thinking of changing the Transmission Th350 for a Th2004r (4 Speed). Has anyone tried this setup?

Greetings from Venezuela🌴
 

ssn696

Living in the Past
Supporting Member
Jul 19, 2009
4,970
113
Permanent Temporary
It will work just fine. You’ll need to modify your crossmember to move the mount towards the rear. You’ll need a lockup kit to make it live without a computer.
 

oldmansmonte

G-Body Guru
Oct 29, 2010
544
63
Buffalo, NY
When you install the transmission you need to install it without the pan on to verify than when you press the gas pedal that the Tv cable it pulling the cable in inserting the plunger 100% when the carb/efi throttle plat hits WOT. If this is not happening you can burn that transmission up fast. And I mean FAST FAST. Carb/EFI needs to have the 2004r bracket for proper geometry. Get that right and this will be a huge upgrade for that car.
 

PBGBodyFan

G-Body Guru
Supporting Member
Mar 3, 2009
574
93
Wisconsin
Being an 83’ it’s computer controlled and should have a lockup converter, so the wiring/plug might work(?). Not sure, just thinking out loud.
 
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Oct 14, 2008
7,081
113
Melville,Saskatchewan
Yes, the plug is the same between the TH250/350C and the 2004R. He probably has the less desirable TH250C, if original. I would think the wiring would be the same. Make sure you run at least 3.42 gearing with a 2004R. Those two changes will make your car much faster and . You will run around 1850 at 60 mph with 2004R/3.42 gear with a stock tire height. You probably have 2.41 gears so you actually drop 100 rpm over your current combo at 60 mph. Another bonus besides the deeper first gear and great .67 OD is the torque converter. I find stock TH250/350 converters stall at a dismal 1600 rpm. Every stock and rebuilt 2004Rconverter, stamped D9, stall around 1900 rpm, 300 rpm makes a big difference in launch. Add dual exhaust and you won't be scared to merge into modern traffic.
 

DRIVEN

Geezer
Apr 25, 2009
7,041
113
*CENSORED*
Even with your monstrous 200hp, I doubt a 1.6 effective final ratio would be much fun.
 

Ribbedroof

Comic Book Super Hero
Supporting Member
Jan 4, 2009
4,040
113
Wellston, OK
Lot of assumptions in this thread, given the poster's location.

* US market car, or other? Not all '83s got computers
* 3.8 could also be 229 Chevrolet engine, 231s are pretty uncommon in Malibus
* Verified TH350? See first bullet point......Could be TH250, TH250C, TH350, TH350C, or even a TH200 or TH200C if just going by pan shape rather than bolt count/band adjustment. etc to lock down what trans is actually in it. Again, will depend on how car was originally configured to get an idea of what OE wiring is or is not present
 
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