th350 to 2004R
Thread Starter
Burning Brakes
Joined: Feb 2011
Posts: 849
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From: Woodland California
th350 to 2004R
I just purchased a 1975 Corvette with a bad tranny.
I'm really considering a transmission with an overdrive.
Been doing some research and the 2004R kind of floated to the top.
I'll probably end up with a 383 and 400 hp.
Is this a good choice?
I have a 6 speed in my 1990 and it's okay, but I want an automatic in the 75.
Any suggestions ?
I'm really considering a transmission with an overdrive.
Been doing some research and the 2004R kind of floated to the top.
I'll probably end up with a 383 and 400 hp.
Is this a good choice?
I have a 6 speed in my 1990 and it's okay, but I want an automatic in the 75.
Any suggestions ?
Drifting
Joined: Jul 2004
Posts: 1,695
Likes: 65
From: Kissimmee fl
Finalist 2021 C3 of the Year - Modified
2017 C3 of Year Finalist
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St. Jude Donor '07
The 200 can be BUILT to handle that much HP. In stock form, they were never put behind a V-8 by the general.
Melting Slicks
Joined: Feb 2007
Posts: 2,136
Likes: 62
From: West Kingston RI
You will also have to either modify your mount holes in the crossmember or get a new one. I bought one from Bowtie Overdrive for my 200 4R conversion on my 75. It's a nice piece. .You will also have to wire up for the lock-up converter, also available at BTO.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Do an internet search on "transmission 200R4 rebuild" and several sources should show up. The 200R is a good choice for your car, as long as it is rebuilt to handle 450-500 hp. When ordering, you should ask that it have a torque converter that is matched to the torque output of YOUR engine and with a stall speed for either street use or performance. If you won't be doing any serious racing, just put a street convertor in it...it will operate smoother in city driving and be more efficient on fuel. Also, tell them what rear axle and rear tire size you have so that they can install the correct speedo drive gear in it...that way your speedo will be calibrated correctly.
Racer
Joined: Jul 2007
Posts: 339
Likes: 4
From: Northwest CT
Racer
Joined: Jul 2007
Posts: 339
Likes: 4
From: Northwest CT
You don't need a new cross member. The 2004R rear mount is in the same place as the TH400. That said, the BTO cross member is a very nice part.
Drifting
Joined: Jul 2004
Posts: 1,695
Likes: 65
From: Kissimmee fl
Finalist 2021 C3 of the Year - Modified
2017 C3 of Year Finalist
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St. Jude Donor '07
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Drifting
Joined: Apr 2003
Posts: 1,323
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From: Castle Hills Texas
But they were put behind the 1987-1989 (however long that run was) Buick Grand National which was no slouch as I recall. I realize the GN was not a V-8 but as I recall it was a pretty tarted up Turbo V-6 that was kicking the crap out of everything else the General was making at the time. How well they held up in the GN, I have no idea.... It would be the tranny of choice if I were going to make the jump.
7th Gear
Joined: Mar 2011
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