I am thinking of doing a mini tub on my 69. Is it as easy as cutting an inch of steel out of the frame rails the length of the tires, and simply welding a .090 patch? Looking at the rear frame rails, there is a couture that moves in about an inch one inch from the top. This looks like it would make a perfect flange to weld to if I were to cut in an inch, but it also looks like a structural design. Any suggestions?

This is exactly what I talked about doing in this post:

http://www.chevelles.com/forum/ultimatebb.php/topic/4/22814.html

It's very straight forward. I did it to a 78 Malibu, but the way it's done is the same.

Check out http://pg.photos.yahoo.com/ph/isracing@sbcglobal.net/album?.dir=1ce3&.src=ph there are pics of my car being minitubbed, and having the frame notched. should give you some ideas... similar to SSSean's car

Good stuff thanks

The part I don't get is how to attach the new tubs to the fender lip.Do you leave part of original inner fender well, say an inch or so , along the fender lip and then weld the new tub to that or do you not worry about it trim the new tub as close as possible and just caulk or epoxy the new tub to the existing fender lip??