Im almost positive im gonna order a vortecpro motor and now I need a trans to put behind it and I dont want to have to do it again.
My car originally had a t-350 with a 12bolt 4.10 gear
Talking to mark I dont really need the 4.10 gear for the street and I dont plan on hitting the track any time soon I just want to drive.
Not really sure about doin an overdrive trans so I thought the t-400 would be my next option.
What is involved?My guess is its just longer and I need to get the driveshaft shortened?
Looking for help any is appreciated.
Thanx

when I traded mine out I had to have my driveshaft shortened and change out the yoke going into the trans. hope this helps

You will also need a T-400 crossmember they are different than the others..and be sure to get the dipstick and tube for the T-400.

Judging by his screen name, he has a '71, so he won't need a new crossmember. All he'll have to do with the crossmember is slide it back.

With a 350 - 400 swap...

You MAY need to shorten the driveshaft.
You will have to find a 32 spline slip yoke to replace your current 27 spline slip yoke.
The shift linkage will be the same.
The kickdown is different, 350's use a cable, 400's just use a electronic switch... easy to do though if you want to use it.
The cooling lines will bolt right in without much effort.
The torque converter will swap straight over if you desire to keep the same one.
The vacuum modulator line will work too, just got to bend it a bit to make it fit.
The trans mount is the same too. So if it's still good, reuse it. But if it's saturated or dry rotted, now's a good time to replace it.
I think that's it.

But... if you got a good running TH350, I'd run it until it breaks, never know, it might last a long time. Just depends on how well it was built, they can hold a good bit of power in stock form if built right too.

If it's a 71 a new crossmember is not needed.

The transmission mounts are NOT the same, they are the same where they bolt to the crossmember, but the bolt pattern on the transmission is wider on a 400, There is a universal aftermarket mount available with slotted mount holes, but are made in India.