TH400 as a DD
TH400's were daily drivers long before there were overdrives. You get used to it unless it's an all interstate car. I'm assuming it's mostly drag racing you do with it.
Pro: strong as a backhoe
con: no overdrive gear
Pro: strong as a backhoe
con: no overdrive gear
I meant the reason you were looking to go turbo 400. I assumed it was for it's strength. It's no harder to live with than any other auto, just uneccessary unless the car's a beast.
Thread Starter
TECH Resident
Joined: May 2006
Posts: 858
Likes: 0
From: SoCal
Are they bad on the interstate? Why? Sorry if these seem like dumb questions but I have never driven in one.
My car with 4.10's and 26" tires is about 3000 RPM at 55 mph. Thats why it's not a good DD tranny, plus the drop in milage. Like posted above, just put your 4L60E in drive and go everywhere like that and see how you like it.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo 
Everything GM made was TH350 and TH400's. My old Z28 was a 4spd manual with no OD, never bothered me a bit. However, once you get used to cruising the interstate with OD at 90mph you get spoiled.
TH400 is like a Dana 60, if you need it because of your insane power get it. If not, why bother?
They are very livable with a 2.73 or 3.23 gear, go lower (3.73 or 4.10) and you won't like it very much.
I run a TH400 in my 94Z. Its a bolt on car nothing too radical but I got tired of breaking drivetrain parts and just went over kill.
It only gets driven on the weekends during the summer so its easy to live with my RMVB TH400 and 4.10s with a spool.
I run a TH400 in my 94Z. Its a bolt on car nothing too radical but I got tired of breaking drivetrain parts and just went over kill.
It only gets driven on the weekends during the summer so its easy to live with my RMVB TH400 and 4.10s with a spool.
TECH Veteran
Joined: Aug 2002
Posts: 4,055
Likes: 1
From: Hartsdale, NY
I used to rebuild these in the 1970s.
They are rock solid - strong as hell! Unfortuntately, no overdrive and one other thing no one else mentioned: they weigh a TON!
I would not recommend this unit for a DD, expecially with gas prices approaching 4 bucks a gallon.
I thought this unit was not used frequently for drag racing either since it weighs too much.
They are rock solid - strong as hell! Unfortuntately, no overdrive and one other thing no one else mentioned: they weigh a TON!
I would not recommend this unit for a DD, expecially with gas prices approaching 4 bucks a gallon.
I thought this unit was not used frequently for drag racing either since it weighs too much.
Mine is not a daily driver and I absolutely hate it on the highway. The city is fun as **** though. Once you get past the fact that your car is going to guzzle gas, its more perception than anything else. If you have a relatively quiet exhaust, dont pay attention to the tach, get into comfortable groove, or better yet set the cruise the highway isnt going bother that much. My problem is that I have a loud exhaust, no cruise, and I worry about my coolant temp running hot so I'm constantly checking that on the highway.
I drove my full tilt RMVB T-braked TH400 in my last 370ci 76mm Turbo Car on the interstate, in town, hell everywhere. It had a 9" with a spool, 3.25 gears, MT 325/50/15 DR's. I could cruise on the interstate 70mph around 3100rpm. The drivetrian didnt mind. The cooling system didnt like it very much. I needed bigger fans. I am going to a TH350 this time around with the new turbo car.
I will say that Vettes and the occasional Viper I meet on the interstate that wanted to play were pissed when I nailed.
I will say that Vettes and the occasional Viper I meet on the interstate that wanted to play were pissed when I nailed.
Ah the memories,
I used to drive my 1966 427/RMVB th400 powered 1975 nova to the track, 30 minutes highway drive with open headers at 5000 rpm.
What really sucked was the time it broke the shift cable and I drove it 5000 or so rpm at like 30 mph stuck in 2nd, that was over an hour drive home. Could've used some ear plugs that night.
I used to drive my 1966 427/RMVB th400 powered 1975 nova to the track, 30 minutes highway drive with open headers at 5000 rpm.
What really sucked was the time it broke the shift cable and I drove it 5000 or so rpm at like 30 mph stuck in 2nd, that was over an hour drive home. Could've used some ear plugs that night.
Ah the memories,
I used to drive my 1966 427/RMVB th400 powered 1975 nova to the track, 30 minutes highway drive with open headers at 5000 rpm.
What really sucked was the time it broke the shift cable and I drove it 5000 or so rpm at like 30 mph stuck in 2nd, that was over an hour drive home. Could've used some ear plugs that night.
I used to drive my 1966 427/RMVB th400 powered 1975 nova to the track, 30 minutes highway drive with open headers at 5000 rpm.
What really sucked was the time it broke the shift cable and I drove it 5000 or so rpm at like 30 mph stuck in 2nd, that was over an hour drive home. Could've used some ear plugs that night.
TECH Veteran
Joined: Aug 2002
Posts: 4,055
Likes: 1
From: Hartsdale, NY
Yeh, when I was building trannies in the mid 70s, a guy came in to the shop with a TH400 race car.
This car - 69 Firebird - had a +500 cube motor with 2 holley 4 barrels mounted on a very high sheet metal intake - no hood. Car was tubbed - Slicks were huge! The cam was so big, the car did not idle.
Anyway, I had to test drive the TH400 on the street after the build. ...That ride I will not forget!
This car - 69 Firebird - had a +500 cube motor with 2 holley 4 barrels mounted on a very high sheet metal intake - no hood. Car was tubbed - Slicks were huge! The cam was so big, the car did not idle.
Anyway, I had to test drive the TH400 on the street after the build. ...That ride I will not forget!
On The Tree
Joined: Feb 2008
Posts: 134
Likes: 0
From: SAN JOSE ,CA
Mine Is A Dd. Hate The High Rpm In The Highway. Im At 3000rpm Going 60mph. Have A Vig 3600 Stall, Stock 3.42's On 17in Rim. Love Driving In The City. But The 4l80e Is The Best Way To Go If Its A Dd. Strong Tranny And Has O.d.