th-400
Thread Starter
Racer
Joined: Jul 2006
Posts: 355
Likes: 0
From: milpitas ca
th-400
is the transmisson worth keeping and rebuilding? ( i have finally desided order my heads/cam/intake package from summit.) and need to know where to keep the 400 or toss that bad bitch cause i hear its a power robber. i was thinkin maybe an auto transmission from a 01 trans am (buddy of mine just wrecked his) would it work? or is that insane amounts of fab work?
Burning Brakes
Joined: May 2007
Posts: 1,150
Likes: 14
From: LaMoille Illinois
get the 400 beefed they are good transmissions!! or if you want overdrive go with the newer but i think there are alot of issues like shortning the drive shaft tunnel modifications etc..
Burning Brakes
Joined: May 2007
Posts: 1,150
Likes: 14
From: LaMoille Illinois
if you want descent highway mileage or a lower rpm at 65 mph put taller gears in the rear end. like a 3.08 or 3.31
i have a 383 sb with a 350 turbo runs about 3000-3200 rpm at 65 with 3.73 rear gears
i have a 383 sb with a 350 turbo runs about 3000-3200 rpm at 65 with 3.73 rear gears
Le Mans Master
Joined: Dec 2007
Posts: 6,422
Likes: 591
From: McHenry Illinois
I have read on this forum that several have changed to an overdrive trans like the 700r4 or the 200r4. They have a lower ratio in first gear and you will get better mileage due to the overdrive. The 200r4 seems to be the most recommended, takes less modifications to install it, but might need to be beefed up a little if you have a lot of torque and hp.
Instructor
Joined: Jun 2007
Posts: 128
Likes: 0
From: San Antonio Texas
I have a 76 with TH350, but I was also wondering if 200r4 would work? I've also heard if I was to get one BOWTIE overdrives was the place. Why waste time beefing it up when you can buy it straight from the source.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
You cannot use a 4L60E trans without a computer. You would have to do an LT1 or LSx engine conversion at the same time, or use a stand alone computer but that's expensive. As far as installation it will bolt up same as a 700R4 conversion (shorten driveshaft, fab crossmember, mod shifter detent plate). If you can buy the whole wrecked T/A that might be the best bet to take the upgadre money and upgrade the whole driveline. Something to think about.
Burning Brakes
Joined: Oct 2001
Posts: 911
Likes: 5
From: TN
400
I am keeping my tubo 400, it has given me no trouble since new. Always have been impressed that a base engine 350/300 could chirp the tires when the ole tubo 400 shifted from first to second, and this was with a 3:08. No shift kit ever installed. My ZZ engine is no match for the turbo 400. The big block 454's could not destroy the turbo 400.
Melting Slicks
Joined: Jul 2005
Posts: 2,545
Likes: 3
From: 406ci SB, AFR 180 Heads - 490 HP @5,600 RPM 529 lb-ft @ 4,100 RPM
Le Mans Master
Joined: Dec 2007
Posts: 6,422
Likes: 591
From: McHenry Illinois
Some of us enjoy doing as many of the modifications ourselves as we can. It's not all about the end result and how fast you can blow money.
Heat = HP loss, Torque converters make heat
Melting Slicks
Joined: Jun 2002
Posts: 2,842
Likes: 99
From: Orrtanna Pa.
Having blown two 700r4's,and two th350's,I decided the 15hp loss the th400 has is well worth the peace of mind I now have. Rated for an easy 850 hp in the Rossler th400 I now have,I feel comfortable ripping an occasional 6500 rpm shift without fear of hearing that God awful crunch.
Match the converter stall to the cam and rear gears and have a blast with the th400.
Match the converter stall to the cam and rear gears and have a blast with the th400.
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
Having blown two 700r4's,and two th350's,I decided the 15hp loss the th400 has is well worth the peace of mind I now have. Rated for an easy 850 hp in the Rossler th400 I now have,I feel comfortable ripping an occasional 6500 rpm shift without fear of hearing that God awful crunch.
Match the converter stall to the cam and rear gears and have a blast with the th400.
Match the converter stall to the cam and rear gears and have a blast with the th400.
And even with the greater HP loss and heavier weight, the actual difference in performance is pretty much unnoticable.
A mid 11 second car might be 1/10 of a second slower with the 400.
Safety Car
Joined: Apr 2007
Posts: 4,435
Likes: 9
From: Kalamazoo Mi
not to hijack, but does anyone run a shift kit in their th400? and if so what one would you recommend for street use with lite auto cross. also what are some good lockup torque converters, and how much of a pita are they to change out?
Steve
Steve
Team Owner
Joined: Jun 2001
Posts: 43,136
Likes: 155
From: Thomson Georgia
I have read on this forum that several have changed to an overdrive trans like the 700r4 or the 200r4. They have a lower ratio in first gear and you will get better mileage due to the overdrive. The 200r4 seems to be the most recommended, takes less modifications to install it, but might need to be beefed up a little if you have a lot of torque and hp.
The 700 R4 is what is Currently being installled in my 74!
I have heard so many good things about them I can hardly wait to see and feel the actual results of the Transfer!!
Thread Starter
Racer
Joined: Jul 2006
Posts: 355
Likes: 0
From: milpitas ca
Ok so i took it in to get rebuilt today......(there goes the head/cams and headers) but i feel like its worth it. what tq converter should i get? the guy at the shop recombend at 2200 stall