TH350 / 400 worth it?

**Transam388** · 08-28-2006, 08:21 AM

Well this weekend I managed to finally break the 4l60E at the drag strip. 3 and 4 are completly not working and 2 is pretty slippery also. I have been told I should put a built TH350 in there instead of a race built 4l60. I am hitting like 525HP and want of course to get a race built tranny that can handle the power. I have a second daily driver so having OD is not a total necessity. Anyway, has anyone done this and is it worth it? What to watch out for, anything you can give aid in this I would appreciate!! Of course any shops in Houston tht might be good as well. Have checked Century and Circle D at this time but any others are welcome! Thanks!

**nosfed** · 08-28-2006, 09:20 AM

Originally Posted by Transam388

Well this weekend I managed to finally break the 4l60E at the drag strip. 3 and 4 are completly not working and 2 is pretty slippery also. I have been told I should put a built TH350 in there instead of a race built 4l60. I am hitting like 525HP and want of course to get a race built tranny that can handle the power. I have a second daily driver so having OD is not a total necessity. Anyway, has anyone done this and is it worth it? What to watch out for, anything you can give aid in this I would appreciate!! Of course any shops in Houston tht might be good as well. Have checked Century and Circle D at this time but any others are welcome! Thanks!

If you are even considering going below 10's then you don't want the th350. It is a great tranny up till that point but it is worth putting the 400 in.

**performabuilt** · 08-28-2006, 04:43 PM

Personally I think your stepping backwards in several ways , your losing considerable ratio in first gear , and with the loss of over drive the ar will be left relativly and unstreetable unit , Since fuel econony will be less than non exsistant , Personaly I wouldnt do it , Though agreed the th400 is a strong unit , Its heavier, gear ratios are less than desiarable ,
I would look around at some 4l60e replacements first , built for your use , they are out there and they can handle what you have and what you doing when built correctly ,
Just and opinion

**Transam388** · 08-29-2006, 08:28 AM

These are the things I want to hear, thank you to you both!! I have started to slide back to getting a built 4L60E as I also learned I would have to change cross braces, torque arms, shifter, get speedometer VSS stuff, etc. So yes at this time a race built 4L60E is looking like the path I will take. Again, thank you for your insights!!

**nosfed** · 08-30-2006, 12:36 PM

Originally Posted by Transam388

These are the things I want to hear, thank you to you both!! I have started to slide back to getting a built 4L60E as I also learned I would have to change cross braces, torque arms, shifter, get speedometer VSS stuff, etc. So yes at this time a race built 4L60E is looking like the path I will take. Again, thank you for your insights!!

As much as I hate to say it, I am gonna have to disagree with performabuilt. THe horsepower you are putting down is up there and the 4l60E cannot handle it even when race built. That is why so many people go to th400's. I agree with the drivabilty part but you should maybe look into the 4l80's then. Tougher tranny, is very costly but will give you the overdrive and the toughness. Buddy of mine runs it in his car and it is an easy 9 second ride. I have seen 60's that are in mid 10second cars last 3 passes sometimes. I used to question whether it was the tranny or the builder but now I know it is more the tranny.