The old webbed extensions had holes on either end but the new ones have holes on only one end.
I would like to still use the old webbed extensions to further extend the new extensions but to do so it seems like I would need to drill 4 oversize 5/16" screw holes (oversized to allow fine adjustment) to line up with the holes on the webbed extension.
The holes would have to go throuh about 3/8" of cast iron.
How hard would it be to drill such holes? - Any special bits? - Or should I take this to a machine shop or something to get it done?