Do yourself a favor and stick with your stock frame. It is much easier to modify it then to try and make a frame from something else work. I learned the hard way. I took a frame out of a 2002 Ford explorer because I like the independent rear suspension and narrowed it. Then I put a mustang II front end on it. Then I had to build a floor from scratch with a support frame between it and the explorer frame. I will have over $30,000 in this car when I am done and I am doing everything but the interior myself. Of course putting a 2006 5.7 hemi in it didn't help with the cost at all.