Thanks for your help and advice. I think I will opt to leave them out. I presume there should be enough clearance between the sub frame and floor to leave the felt pads out so as to not cause any vibration issues. I don't suppose you could also advise me on another issue I have. I have put a new boot floor in the rear using a genuine heritage panel. The problem is the new panels are for an injection car because the hole for the fuel lines is a large oval as opposed to the two holes for the fuel lines. I have made a plug up to weld the fuel injection hole up and I plan to drill the original holes in for the normal carb fuel lines. You wouldn't happen to be able to tell me the measurements so I could drill the fuel pipe holes out please ? Or do you have any other suggestions ?
On my 97mpi it had rubber pads instead of felt. It trapped water too but nowhere near as bad as felt.
Always took them out and never noticed a difference in noise emissions...
Legend would have it that the pads where used as shims for fitting the subframes without scratching the paint...
The only floors are late injection and will need modifying as you intend on doing, have you not got the old floor to get the size of the holes or maybe the grommet that fits in it?