Got a long ways to go on these but thought I would post what little I have done and describe what I'm planning.
I had planned to use that other set of rails but the stand offs are a different length, so I left them alone and will modify only the old set of L67s.
First I just cut the rails free of the cross over lines.
Tried using a dremmal but the cut off wheels kept braking so I went with my big disk cutter.
I cut a little above the weld so I don't think the fuel line. After I cut threw the first side I pulled it open with a channel locks.
Then cut the other side and broke it off.
This left a rough cut.
Then started cleaning it up.
Don't care if they are perfect at this point. Just getting started.
Got started on the front rails. Taking a brake now.
My plan is to cover the remaining stock rails with a aluminum cover. Something I can pop on top, perhaps hold in place with JB weld. Just to make it look good. I'll get some threaded ends brazed on the rails to attach flexible fuel hose. The FPR will be mounted on the rails some where. Should make a easy cheep build.