Trans mounting location

[curtish57]

Hi all, I am building a 454 with a th400 and dropping it into my 70, hopefully soon. My car is a 350/350 originally. My question is about the trans crossmember mount location. Is it in the same place for the 350 and the 400 or do I need to move it back? Thank you. 

[cny first gen 71]

I think it has to be moved back and I believe the holes are there for it. I'm sure someone else will chime in that knows for sure.

[Dtret]

I don’t know on a small block car because, honestly I never paid attention. But the first picture is of my 70 SS frame ( 454 th400) for reference. The second picture is I of the  mount holes, you can see the washer mark towards the front bolt and the other would be the rear hole with hardly no washer marks. The third picture is of my 71SS ( 454 th400). That should give you what you need. 

[curtish57]

Yep that is super helpful thank you. I have the same holes just like your but my crossmember is mounted all the way forward

[714024SPEED]

Just move it back holes are already in the frame from the factory.

[Dtret]

10 hours ago, curtish57 said:

Yep that is super helpful thank you. I have the same holes just like your but my crossmember is mounted all the way forward

Check out your crossmember and make sure the ends are not rusted away.