I finally got around to installing my frame extension and cross member today. This is for the TH400 or 200-4R cross member on the pre-'83 G-bodies. The extension and cross member both came with bolts, washers and nylon lock nuts. It's not terribly difficult but I figured I'd do a quick write up if anyone else is planning to do it. If you can operate a drill you can figure it out. :lol:
First thing I did was a quick mock up to make sure everything would line up once the holes were drilled.
Here's the extension in place before drilling
The two holes closest to the outside of the frame rail will be center punched to mark the drilling points
Frame after drilling. I suggest using a few smaller pilot bits and some cutting oil to prevent burning up your bits
Here's the extension in place with the existing pilot holes. These will need to be drilled out to 1/2" as well.
Bolted in place...I anti-seize everything!
If you did everything correctly, everything will bolt right in place
First thing I did was a quick mock up to make sure everything would line up once the holes were drilled.
Here's the extension in place before drilling
The two holes closest to the outside of the frame rail will be center punched to mark the drilling points
Frame after drilling. I suggest using a few smaller pilot bits and some cutting oil to prevent burning up your bits
Here's the extension in place with the existing pilot holes. These will need to be drilled out to 1/2" as well.
Bolted in place...I anti-seize everything!
If you did everything correctly, everything will bolt right in place