when i swapped to 4 speed in my 68 valiant i fitted small nutserts to the original floor and tunnel around the new hole. that way i could bolt the 4 speed hump in place which with it removed made installing to shifter rods much much easier. just something to consider before you weld yours in place for good.
neil.
Neil, I like your idea!! On my triumph tr6 ,for the trans tunnel, I welded in 1/4 weldable nuts, nutserts sounds easier;) Do you buy those as a kit, like rivets?