I am thinking about coverting my 350 in my 72 442 to a 400. I have a 455 that was built to a little of 400hp. The transmission is about the only thing I did not address when I restored the car and I think now is the time to do so. I have been looking at the 400 transmissions from Summit. My transmission looks like is a short tailshaft, I would say about 6". I was trying to find a previous thread on the site that I saw that talked about converting to a 400 but I cant seem to find it. My question more than anything is, am I going to have to lenghten the drive shaft or will I need to have it cut down?

 

Is your engine stock? The reason I ask is the T350 is a good transmission for most applications. It may be easier and/or considerably less expensive to work with what you have. T350's can be made to handle a lot of HP.

To answer your question, The T400 will bolt right up as long as it is from a buick, olds or pontiac. You will have to mod your driveshaft, move the trans xmember back approx 6" (the bolt holes are there already), and mod your intermedate cable routing or replace with one for a T400. You will need a kickdown switch mounted on your gas pedal or carb linkage for passing gear. You may or my not want to revaluate your torque converter at this time.

 

The engine is close to stock. It was bored .40 over and cam was added. I am not sure what size of cam however.

 

You'll need a 400 gas pedal assembly with the electronic down shift capability.
The turbo 350 downshift is cable operated..the 400 electric.

 

Is there anything wrong with the T350?

 

Ir appears to shift too fast from 1st to 2nd. Also it seems hesitant when I put it in reverse. It just might be to my benefit to take it too a transmission shop and have them look at it. I just thought that maybe it would be best to upgrade.

 

Your probably looking at a $1500-2000 expense to go to a T400 If you'd like to compare.