O.K., first off I know I should have run this by you folks before I started.....but the fact is I didn't, so I'm doing it now.
I'm stretching my '76 CJ-7 frame and body 17''. I cut the frame in front of the forward rear spring hanger. I had my local metal supplier form some 12g into C-channels, 33'' long, they will be inserted 8'' inside the frame, and plug welded through holes in the original frame. Then (2) 17'' channels, (1) 12g and (1) 3/16'', will be fitted over the top and plug welded to the inserts and butt welded to the cut frame, as well as welded to each other.
So, my questions at this point are.....
1) Does anyone see any glaring mistakes in the overall plan? (Besides all the overlap surfaces, which I don't see a way to avoid. Weld-thru primer will be used.)
2) (This is my main concern at this point) How much plug welding do you feel is needed to adequately secure the inserts to the original frame?
I was thinking about (4 or 5) 3/4'' holes in each side face,(approx.4 1/2'' x 8'' surface) and (4) 1/2'' holes in each top and bottom.(approx.2 1/2'' x 8'' surface) I am not sure if that would be enough. Obviously I want to get enough holes drilled through the frame before the inserts are in. I don't have any bits bigger than 1/2'' so I will be getting a uni-bit or something for this job, and want to make sure what I get is big enough.
Thanks for making it to the end of this post. If anything is unclear, pipe up and I will try to explain things better.
I welcome all comments, criticisms and questions.
Below are links to a couple write-ups that have inspired me.
Rick Neil's looong cj