Time to start thinking about an Auto. TH400 builders

[eLeSthree]

I'm not saying I'm ready to start the swap, but if a guy wanted to do some research, where would he start looking.

A quick search shows plenty of lists of necessary items, but I'm just not sure who I would purchase the trans from.

I'd like somethinig rated around 1500hp. A local South Florida shop would be preferred in case of warranty issues and shipping.

I figure if I am going to ditch the manual it's gonna be a racecar with a cage and might as well ditch over drive and some weight. Hell I never go far with it anyway. 4k miles in 5 years of owning it. So leaning th400 over 6l80.

Any suggestions?

[BuddyLee]

Is the TH400 that you are considering a 4 speed? I run the TH400 in the Grand National and it has always held up well for both track and street.

[Vegas Bound]

Stay away from the trans builder in Indiana. I got a stage 5 4L80e from them that lasted 2200 miles.

[Bo White]

Th400 ftw

[Bo White]

Th400 is a 3 speed.
Lots of top trans shops across the nation can do a nice th400. Call around and go with your gut.

[Silver14]

Originally Posted by Vegas Bound

Stay away from the trans builder in Indiana. I got a stage 5 4L80e from them that lasted 2200 miles.

RPM?



Why be vague, just say the whole story. What failed in it?

[Tommy434]

I did the 4l80 swap in my 14 wasn’t the worst thing I’ve ever done the 400 won’t be quit as bad you won’t have all the wiring crap I had to deal with. I’m on the middle of swapping the zL1 rear diff to a 9” may have some parts for sell in the future. There’s some good info from Diet Coke( guy on here) it helped me out a ton. You will have to do some fab work. Tommy

[Vegas Bound]

Originally Posted by Silver14

RPM?



Why be vague, just say the whole story. What failed in it?

Yes. I had it rebuilt in Dallas and the builder said pretty much everything in the trans was stock GM parts. That isn't a stage 5 build to me.


The only person I would want running one of their transmissions is the guy in the other lane. Guaranteed win for me.

[Silver14]

Originally Posted by Vegas Bound

Yes. I had it rebuilt in Dallas and the builder said pretty much everything in the trans was stock GM parts. That isn't a stage 5 build to me.


The only person I would want running one of their transmissions is the guy in the other lane. Guaranteed win for me.

What did RPM say about it?

[eLeSthree]

Originally Posted by Bo White

Th400 is a 3 speed.
Lots of top trans shops across the nation can do a nice th400. Call around and go with your gut.

Yea seem pretty popular. I was kind of expecting it would need refreshing at some point so i wanted to go with a local shop. Looking in the South Florida area. My track is kinda far, so i may miss the overdrive.

Does the th400 not have provisions for wiring it up to shift automatically? Must it be manual bumped into gear?

[Bo White]

Its a vacuum modulated transmission. No wiring.

[Vegas Bound]

Originally Posted by Silver14

What did RPM say about it?

They said, and I quote, "it's after the 90 day warrantee, not our problem".

[BuddyLee]

Originally Posted by Bo White

Th400 is a 3 speed.
Lots of top trans shops across the nation can do a nice th400. Call around and go with your gut.

Bo, is the OD not counted as a speed? One, two, three, and OD.

[Vegas Bound]

Originally Posted by BuddyLee

Bo, is the OD not counted as a speed? One, two, three, and OD.

TH400 doesn't have OD. 4L60/65/70/80 etc are the OD version of the older TH350/400.