which transmission to use?

[Jacobskeeper]

hello out there , nice cars on this site. im glad i found somewhere to get a little help. im restoring my 1988 monte carlo luxury sport. it came stock with a 4.3 l v6 , but i want to put a 69 sbc 350 4 bolt main in it. i have the motor rebuilt on an engine stand, pics soon to come. im running into issues on whether to keep my stock th2004r transmission or but the th350. i think i would have to have the transmission built up some , but sum people tell me i could use the transmission stock if i dont beat on it?? im not running track or using boost, i just want a daily driver with balls! if anyone could offer thier opinion id appreciate it

 

[clsmith1424]

i would use the th350 as the 2004r is not built to handle the constant torque of the sbc.

 

[jordanfr13]

What do you plan on using the car for? Any highway driving? And what kind of gears do you have in it right now? It might be well worth it to put a bit of money into the 200-4r so you can keep your overdrive.

 

[dogsht]

Since this is a street car leave the 3 speed in the 70s. The 200-4R allows for acceleration gearing such as 3.73s And low wear & great mileage on the road. Just get the 200-4R done by a shop that has experience in building high performance versions of the 200-4R. I had good luck with www.extremeautomatics.com $1,395 guaranteed to 500HP 10.90 ets behind a stout 509ci 442 seen in my pics. Oh yea get a switch to keep your lock up converter locking up on the highway. It usually saves 200 to 300 rpms and about 1mpg on the highway. I would even rather finance it then lose acceleration and make larger gas payments.

Another idea since you already have the advantages of a intank fuel pump keep it. Check out a Mallory 4309 return style regulator as seen at jegs.com etc. Use your existing feed & return lines etc. just add the regulator in place of the fuel rail and a line from it to the carb. No old mechanical pump or loud unreliable gravity fed out of tank electric fuel pump either. Cheaper easier and better.

 

[kornball426]

Th350 will be cheaper by quite a few hundred dollars. But if you plan to do a lot of street driving, the extra cost of building an overdrive transmission like a 700R4/4L60, 4L60E or 200R4 can be outweighed by the extra fuel mileage and reduced engine wear of having an overdrive transmission.

If you plan to keep it under 60mph and only do track or in town driving, and no highway use except very occasionally then I'd save the money and go TH350. If you plan to cruise at 60+ mph for extended periods on a regular basis there is no doubt go for the overdrive trans.

4L80E trans is a bad ****... but it can be pricey to make it work in older vehicles.

 

[Phoenyx]

I have 3.73s and a TH350. Sure wish I had a 2004r...

 

[beermonkey9417]

i got a 4.11 gear and a th350, i wish i had an extra gear. :|

 

[tc1959]

I run a 700 r-4 with a 3:24 gear In my 78 El Camino. Just like GM designed In the Camaro ,Caprice, Corvette, ECT. MY trans came out of a 91 Caprice police car, IT has heavy duty Input shaft, larger clutch packs, heaver duty ft. pump, auxiliary valve body.The 700 trans also came in about 200 million GM trucks That's good enough for me
GM hydra matic transmissions are rated by the amount of torque and horsepower they can handle.
200, 2004-r, 250,350,400,7004-r, 4L60E,4L80E, ect...
As far as I know the 200 4-r was known for having sun gear problems and numerous other internal weaknesses, many can be corrected with aftermarket up grades. So I guess it's all up to how much money do you want to spend,And how you are going to use the car.
My car came with a THM 350 and after tearing the center support lugs out of three different cases with my mild 350 engine.
I gave up and went with the 700 that was ten years ago and I have no regrets.

 

[79loserbluebu]

Anyone who says to use a 3.73 geared car with a TH350 has got to be wacked. I'd stick with the 2004r not only because it's a good transmission, but also you keep your stock length driveshaft. GM is still having problems with the sunshells in transmissions, so there's no real loss to have the 2004r. Like said before, take it to a shop that's gone through their share of them and put a couple bucks into it. If I was keeping a Gen 1 SBC in my car I'd swap to a 2004r over this wintertime. 3.73 and TH350 on the highway is not fun at all.

 

[TURNA]

I would use the 2004r the way it is till it goes as long as it is working fine now.


In the meantime do your research and find a somewhat local shop that knows how to rebuild them.

DO NOT just go to any transmission shop for a rebuild or an upgrade.