You can weld an extension to the standard roll bar, but it will still be a standard roll bar which is of lighter material than an FIA bar and the hood will probably not fit, so personally I wouldn't bother. Standard bar, even with welded on extension will not be accepted for L7C events.
If you're changing, go for the FIA bar.
Paul Richards
Area Representative - L.A.D.S. (Lancashire and District Sevens)
LADS Website
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